Step-by-step explanation:
[tex]\tt{ -15b+2b-(-7b)= -12 }[/tex] ⠀
[tex]\tt{-15b+2b+7b=-12 }[/tex] ⠀
[tex]\tt{-15b+9b=-12 }[/tex] ⠀
[tex]\tt{ -6b=-12 }[/tex] ⠀
[tex]\tt{b=\dfrac{-12}{-6} }[/tex] ⠀
[tex]\tt{ b=2 }[/tex] ⠀
Answer:
Step-by-step explanation: