1. -5(3m+6) = -3(4m-2)
We must open the parenthesis and multiply every term inside the parenthesis by the number outside the parenthesis so :
-5*3m - 5*6 = -3*4m - 3*(-2)
-15m - 30 = -12m +6 | +12m
-15m +12m -30 = 12m+12m + 6
-3m - 30 = 6 | +30
-3m - 30 + 30 = 6+30
-3m = 36
m = -36÷3
m = -12
2. -7(k+9)=9(k-5)-14k
Here we'll do the same thing :
-7*k - 7*9 = 9*k - 9*5 - 14k
-7k - 63 = 9k - 45 -14k
-7k - 63 = - 5k - 45 | + 5k
-7k+5k -63 = -5k + 5k - 45
-2k - 63 = - 45 | + 63
-2k - 63 + 63 = -45 + 63
-2k = 18
k = -18÷2
k = -9
