it multiplies the m and 2 by the 2, giving the 2 to the 2 numbers in the parentheses, turning 2 (m+2) into 2×m and 2×2, getting 2m+4=22, and to get m, you first take away the 4 by subtracting 4 from both sides, then dividing 18 and 2m by 2 to get m=18