Solve using substitution. 6x+y=7 10x+7y=-15 square square

To solve the system of equations using substitution, we can solve one equation for one variable and then substitute that expression into the other equation.<br /><br />Let's solve the first equation for y:<br />$6x + y = 7$<br />$y = 7 - 6x$<br /><br />Now we can substitute this expression for y into the second equation:<br />$10x + 7y = -15$<br />$10x + 7(7 - 6x) = -15$<br />$10x + 49 - 42x = -15$<br />$-32x + 49 = -15$<br />$-32x = -64$<br />$x = 2$<br /><br />Now that we have found the value of x, we can substitute it back into the expression for y:<br />$y = 7 - 6x$<br />$y = 7 - 6(2)$<br />$y = 7 - 12$<br />$y = -5$<br /><br />Therefore, the solution to the system of equations is $x = 2$ and $y = -5$.