Could someone me with these systems. i have to use substitution.
-7x+2y=18
6x+6y=0
show your steps so i can learn too. you.

The perimeter of a rectangle is 42 inches. if the width of the rectangle is 6 inches, what is the length

Which statement is true about a number and its additive inverse? a. their product is always one. b. their sum is always one. c. they are always reciprocals of each other. d. their sum is always zero.

Awoman has 14 different shirts: 10 white shirts and 4 red shirts. if she randomly chooses 2 shirts to take with her on vacation, then what is the probability that she will choose two white shirts? show your answer in fraction and percent, round to the nearest whole percent.