Answer:
her first mistake was on line 3.
line 1: 80 + [2(3 1/2 + 1 1/2)]
line 2: 80 + [2(5)]
line 3: 80 + 10
line 4: 90
Step-by-step explanation:
on line 3 she added 80 + 2, but she should have multiplied 2 by 5. the correct steps would be:
line 1: 80 + [2(3 1/2 + 1 1/2)]
line 2: 80 + [2(5)]
line 3: 80 + 10
line 4: 90
Use subsiution]
y=-3x+5
subsitute -3x+5 for y in second equation
5x-4(-3x+5)=-3
distribute
5x+12x-20=-3
add like terms
17x-20=-3
add 20 to both sides
17x=17
divide both sides by 17
x=1
now subsitute 1 for x
y=-3x+5
y=-3(1)+5
y=-3+5
y=2
x=1
y=2
Answer:
-4x^2, -3x, -5
Step-by-step explanation:
-4x^2 + 2x - 5 (1 + x)
-4x^2 + 2x - 5 + 5x
-4x^2 - 3x - 5
Answer:
Step-by-step explanation:
Letters are variables and those variable can store a number
Ex: x=5 y=2
evaluate : 3x+2y
we know that x is 5, so we know that 3x would be 15
we know that y is 2, so we know that 2x would be 4
then it says to add 3x and 2y, we would add 15 and 4 to get 19
(This is a very simple example, when you get older, the expression would be much more confusing.
It is 20 because if u divide 78 by 3.75 ( 3 3/4 ) than equals 20.8
