Answer:
maggie
Step-by-step explanation:
Hello! So, the train travels 80 miles in an hour. 90 minutes is equivalent ot 1 ½ hours. In case you don't know, ½ of 80 is 40. To find the distance gone in 90 minutes, we can just add 80 and 40. 80 + 40 is 120. Another way to solve it is to multiply 80 by 1.5 and you would still get the same answer. There. The train will have gone 120 miles in 90 minutes.
Answer:
(4,12)
(-1,-3)
Step-by-step explanation:
x^2 - y = 4
y = 3x
Use substitution. Substitute 3x for y in the first equation
x^2 - (3x) = 4
x^2 -3x =4
Subtract 4 from each side
x^2 -3x -4 = 4-4
x^2 -3x-4 =0
Factor
(x-4) (x+1) =0
Using the zero product property
x-4 =0 x+1 =0
x=4 x=-1
Now to find y for each x solution
x=4
y =3x = 3(4) =12
(4,12)
x=-1
y =3x = 3(-1) =-3
(-1,-3)
Yes because if you add forty and thirty that equals seventy plus twenty is 90 which is a right angle
