Question

C an anyone solve this 3(2b + 3)2 = 36 and if so what is it

Answer 1

Assuming it's linear:

3(2b+3)2 = 36

6(2b+3) = 36
12b + 18 = 36
12b = 18
b = 1.5

Assuming you meant to put the 2 as an exponent:
3(2b+3)² = 36

First do the exponent:
3(4b² + 12b + 9) = 36

Multiply it out:
12b² + 36b + 27 = 36
12b² + 36b - 9 = 0

Factor:
3(4b² + 12b - 3) = 0

Apply Quadratic Formula:

x = (-12 +- √(144 + 48)) / 8
x = (-12+√192) / 8 and x = (-12 - √192) / 8

This makes it so that the variable you're solving for = .232 and -3.232.

Answer 2

$3(2b + 3)^2 = 36$

Divide by 3 on both sides:
$(2b + 3)^2 = 12$

Square root both sides:
$2b + 3= \pm \sqrt{12}$

Take away 3 from both sides:
$2b= \pm \sqrt{12} - 3$

Divide by 2 on both sides:
$b= \dfrac{ \sqrt{12} -3 }{2} \ or \ b= \dfrac{ -\sqrt{12} -3 }{2}$

Answer:
$b= 0.23 \ or \ -3.23$