x=12-y sub that for x in other one first divide that one by 2 to make it easier 2x-y=18 2(12-y)-y=18 24-2y-y=18 24-3y=18 minus 24 both sides -3y=-6 divide -3 y=2
D is answer
2. find intersection of x+y=5 and -2x+3y=6 or easiers, just test the intersections wait, they all intersect in the same place this is super easy pick ANY point that is in that reigon and see if it is true
A, if we pick lets say (5,5) that is false for x+y<5 not A
B pick (10,0) false for first one not B
C pick (0,0) true for first false for 2nd not C
D. pick (-10,0) true for first true for 2nd
answer is D
8. time times object=time taken
35 for wall frame or door=21 the first equation has to be in terms of minutes 2nd has to be in terms of loads
first one is 35w+21d=595 2nd is 9w+13d=267 D is answer
