X²+10x+21=0
/\ = 10²-4*1*21
/\ = 100 - 84
/\ = 16
x = (-10+/-\/16)/2
x = (-10+/-4)/2
x' = (-10+4)/2 = -6/2 = -3
x" = (-10-4)/2 = -14/2 = -7
S: {-3; -7}
0.7 repeating is the answer
Answer:
Step-by-step explanation:
to solve this system of equations we will add them
x-3y=-12
2x+3y=3 now +3y-3y=0
3x=-12+3
3x=-9
x=-3
plug in the first equation
-3-3y=-12
-3y=-12+3
-3y=-9
y=3
40 miles an hour and yeah..
