Mathematics Questions and Answers – Solving Linear Equations with Variables on One Side and Number on the Other

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This set of Mathematics MCQs for Class 8 focuses on “Solving Linear Equations with Variables on One Side and Number on the Other”.

1. Find the solution for the equation 3x + 3 = 4.
a) 3
b) \(\frac{1}{3}\)
c) 4
d) \(\frac{1}{4}\)
View Answer

Answer: b
Explanation: 3x + 3 = 4
Step 1: Subtract 3 from both the sides,
3x + 3 – 3 = 4 – 3
3x = 1
Step 2: Divided both the sides by 3,
x = \(\frac{1}{3}\)
So, we have solution for the equation x = \(\frac{1}{3}\)
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2. In equation 3x + 4 = 10, by transposing the variable on RHS we get ________
a) -4 = 10 – 3x
b) 4 = 3x + 10
c) 4 = -3x + 10
d) -4 = – 3x – 10
View Answer

Answer: c
Explanation: While shifting the variable from LHS to RHS the sign changes from positive to negative and vice versa. Here, the given equation is 3x + 4 = 10.

3. Solve equation 7x + 14 = 21 to find value of x.
a) x = 1
b) x =-1
c) x = 2
d) x = -2
View Answer

Answer: a
Explanation: 7x + 14 = 21
Step 1: Solving the equation, we take constant 14 on the RHS making 7x = 7
Step 2: Dividing LHS and RHS with 7 we get x = 1.
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4. Solve: \(\frac{5}{2}x + \frac{3}{2} = \frac{6}{4}\).
a) x = 1
b) x = 2
c) x = 3
d) x = 0
View Answer

Answer: d
Explanation: \(\frac{5}{2}x + \frac{3}{2} = \frac{6}{4}\)
Step 1: Reducing the fraction we get,
\(\frac{5}{2}x + \frac{3}{2} = \frac{3}{2}\)
Step 2: Multiplying LHS and RHS by 2 we get,
5x + 3 = 3
i.e. 5x = 0
Step 3: Dividing both sides by 5 we get,
x = 0.

5. Solve: 7x – 2 = 3.
a) x = \(\frac{5}{7}\)
b) x = \(\frac{7}{5}\)
c) x = \(\frac{3}{5}\)
d) x = \(\frac{5}{3}\)
View Answer

Answer: a
Explanation: 7x – 2 = 3
Step 1: Transposing -2 on RHS we get,
7x = 5
Step 2: Dividing both sides by 7 we get,
x = \(\frac{5}{7}\).
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6. Pick the equation from the given one’s which have solution as z = 2.
a) 2z -2 = 3
b) 3z -2 = -2
c) 3z -3 = 3
d) 4z + 3 = 3
View Answer

Answer: c
Explanation: Solving the 3z – 3 = 3 we get,
Step 1: Transposing -3 on RHS we get,
3z = 6
Step 2: Dividing both sides by 3 we get,
z = 2
Hence, this is the solution of our question.

7. Pick the equation which has the solution in the form of prime number.
a) 2x = 3
b) 3z = -6
c) 4y – 3 = 2
d) 2z – 2 = 2
View Answer

Answer: d
Explanation: A prime number is the number which can be formed by multiplying only two numbers which are 1 and the number itself.
Solving equation, 2z – 2 = 2
Step 1: Transposing – 2 on RHS we get,
2z = 4
Step 2: Dividing equation by 2 we get,
z = 2
Since 2 is greater than 0 and can be formed only by multiplying 1 and 2 it is a prime number.
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8. Solve: 16 = 3m – 2.
a) m = -5
b) m = 5
c) m = 6
d) m = -6
View Answer

Answer: c
Explanation: Step 1: Transposing – 2 to LHS we get,
18 = 3m
Step 2: Dividing both the sides by 3 we get,
m = 6.

9. What is the solution of the equation, 7 + 2x = 0?
a) \(\frac{2}{7}\)
b) \(\frac{-2}{7}\)
c) \(\frac{7}{2}\)
d) \(\frac{-7}{2}\)
View Answer

Answer: d
Explanation: 7 + 2x = 0
Step 1: Transposing 7 to RHS we get,
2x = -7
Step 2: Dividing both sides by 2 we get,
x = \(\frac{-7}{2}\).
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10. The solution of equation 3x + 6 = -3 is x = -3.
a) True
b) False
View Answer

Answer: a
Explanation: 3x + 6 = -3
Step 1: Transposing 6 to RHS we get,
3x = -9
Step 2: Dividing both sides by 3 we get
x = -3.

Sanfoundry Global Education & Learning Series – Mathematics – Class 8.

To practice Mathematics MCQs for Class 8, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer & SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage, Advanced C Programming, SAN Storage Technologies, SCSI Internals & Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him @ LinkedIn | Youtube | Instagram | Facebook | Twitter