Find the sum of coefficients for 2x + 3x + 6x. To solve, add the coefficients together: 2 + 3 + 6 = 11. You can do this because 2, 3 and 6 are coefficients of the same variable, x.
Find the sum of coefficients for 8x - 5x + 12x. To solve, add the coefficients together: 8 - 5 + 12 = 15. You can do this because 8, -5 and 12 are coefficients of the same variable, x.
Find the sum of coefficients for 3x + 9y + 5x + 11y. First, add the coefficients of x together: 3 + 5 = 8. Next, add the coefficients of y together: 9 + 11 = 20. Put the equation back together with the sums: 8x + 20y. Therefore, 8x + 20y represents the sum of coefficients for the expression 3x + 9y + 5x + 11y.