2a(5-b)=3b+7 solve for b step by step

2a(5-b)=3b+7

[open bracket]
10a - 2ab = 3b + 7

[solve for b, so we need to move all terms with b to the left]
[-3b on both sides]
10a - 2ab - 3b = 3b + 7 - 3b
10a - 2ab - 3b = 7

[move all those without b to the right]
[-10a on both side]
10a - 2ab- 3b - 10a = 7 - 10a
-2ab - 3b = 7 - 10a

[divide by -1 through to change b to be positive]
2ab + 3b = 10a - 7

[take b out as the common factor]
b(2a + 3) = 10a - 7

[divide by (2a+3) through]
b = (10a -7)/(2a+3)

What is the last question i don’t see it?

Do the math. she originally had 50 dollars on her gift card and she had 12 dollars left on her gift card after she finished her shopping spree. if you subtract 50 minus 12 you get thirty eight dollars as your answer. so therefore, ciara spent 38 dollars total o