Answer:
a+4=11b
Explanation:
Distributive property in mathematics means to multiply the sum by a number of two or more add-ons will provide the same result that each add-on multiplies by a single number and then together add the products.
for example a( b+c) = ab+ac
Therefore, applying distributive property in asked eapression
12(2a - 6b+ 8) = 21(2a−6b+8)
24a+72b+96 = 42a-126b+168
198b=18a+72
9a +36=99b
3a+12=33b
a+4=11b