How to solve the equation 5x + 3 = 2 * 4 + (X-2) * 6?

How to solve the equation 5x + 3 = 2 * 4 + (X-2) * 6?


5x+3=8+6x-2*6
5x+3=8+6x-12
6x-5x=3+12-8
x=7



Given 4x ^ 2 + 7x-12 = 4, find the value of - 12x ^ 2-21x


Because 4x ^ 2 + 7x-12 = 4
So 4x ^ 2 + 7x = 16
Then 12x ^ 2 + 21x = 48
So - 12x ^ 2-21x = - 48



Given 4x & # 178; + 7x + 2 = 4, find the value of - 12x & # 178; - 21x


Solution
4x²+7x+2=4
4x²+7x=2
∴-12x²-21x
=-3(x²+7x)
=-3×2
=-6



Given 4x ^ 2 + 7x-1 = - 3, find the value of - 12x ^ 2-21x


4x²+7x=-2
Double - 3
-12x²-21x=6