You want to take the -6 outside the parenthesis and multiply it by everything inside the parenthesis. So, -6*7=-42, and -6*t=-6t. Then, take the -42 and add it to both sides of the equation to get the -6t alone. -24-(-42) would become -24+42 which is 18. The new equation is -6t=18. Next, you want to get t alone by -6 on both sides of equation. 18/-6= -3, therefor t= -3.
