Desmond has w marbles and Mandy has 1/2 w marbles. Desmond gives one-tenth of his marbles and Mandy gives two-fifths of her marbles to their cousin Joel. Write an expression for the number of marbles Joel receives.

The value of x in this system of equations is 1. 3x + y = 9 y = –4x + 10 substitute the value of y in the first equation: combine like terms: apply the subtraction property of equality: apply the division property of equality: 3x + (–4x + 10) = 9 –x + 10 = 9 –x = –1 x = 1 what is the value of y?