Question

Solve the equation 25z2 − 140 = 29 by using square roots.
A. z = ±13/5
B. z = ±7/5
C. z = ±29/7
D. no real solutions

Answer 1

The answer is A. Z=+-13/5

Answer 2

Answer:

Option A, $z =$ ± $13/5$

Step-by-step explanation:

Step 1:  Add 140 both sides

$25z^2 - 140 = 29$

$25z^2 - 140 + 140 = 29 + 140$

$25z^2 = 169$

Step 2:  Divide both sides by 25

$\frac{25z^2}{25} = \frac{169}{25}$

$z^2 = 6.76$

Step 3:  Square root both sides

$\sqrt{z^2} = \sqrt{6.76}$

$z =$ ± $2.6$

$z =$ ± $13/5$

Answer: Option A, $z =$ ± $13/5$