You can use the regrouping
Answer:
(2,-3)
Step-by-step explanation:
I am not sure if you meant the first equation to be y or -y. I solved it as y.
y = x-5 -x -3y =7
I am going to take the second equation and write it as x =
-x - 3y = 7 Give equation
-x = 3y +7 Add 3y to both sides
x = -3y-7 Multiplied each term in the equation by -1 so that x could be positive
I am going to substitute -3y-7 for x in the first equation up above
y = x - 5
y = -3y -7 - 5 Substitute -3y-7 for x
y = -3y -12 Combined -7-5
4y = -12 Added 3y to both sides
y = -3 Divided both sides by 4.
I now know that y is -3, I will plug that into x = -3y-7 to solve for x
x = -3(-3) -7
x = 9-7 A negative times a negative is a positive
x = 2
Answer:
$20.00
Step-by-step explanation:
600 ÷ 30 = 20
Answer:
150
Step-by-step explanation:
30 + 30 + 45 + 45 = 150
Answer:
- 35 5-lb weights
- 25 3-lb weights
Step-by-step explanation:
Let t and f represent the numbers of three- and five-pound weights. The problem statement tells us ...
f + t = 60
f - t = 10
Adding these two equations, we get ...
(f +t) +(f -t) = (60) +(10)
2f = 70 . . . . . eliminate parentheses
f = 35 . . . . . . divide by 2
She has 35 5-lb weights, and 25 3-lb weights.
