Question

12=
–
2(
–
2+10b)+19b
b=

Answer 1

Assuming the equation is 12 = −2(−2 + 10b) + 19b, solve for b:

Expand: −2(−2 + 10b) = 4 − 20b, so
12 = 4 − 20b + 19b = 4 − b.

Then 12 − 4 = −b ⇒ 8 = −b ⇒ b = −8.

Check: −2(−2 + 10(−8)) + 19(−8) = −2(−82) − 152 = 164 − 152 = 12. Correct.