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WAEC Mathematics 2021 Paper

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Question : 3

Total: 49

Solve: 2

^{\sqrt{2x+1}}

= 32

13
24
12
11

Solution:

Concept:

Express both sides as powers of the same base, then equate the exponents.

Explanation:

Write

32

as a power of

2

:

32 = 2^5

.

So,

2^{\sqrt{2x+1}} = 2^5

.

Since the bases are equal, equate the exponents:

\sqrt{2x+1} = 5

.

Square both sides:

2x + 1 = 25

.

Subtract

1

from both sides:

2x = 24

.

Divide both sides by

2

:

x = 12

.

Answer:

x = 12

Correct option: C. 12

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