30 students.....14 are boys...that means (30 - 14) = 16 are girls
if 2 boys are dropped......14 - 2 = 12 boys
and 2 girls are added......16 + 2 = 18 girls
fraction of the class that are boys is : 12/30 which reduces to 2/5 <==
Subtract 10x
10x + y = -19
10x + 3y = -17
You would get:
-2y = -2
Two negatives make a positive number! Divide
y = 1
Plug in
10x + (1) = -19
10x = -20
Divide
x = -2
Your solutions are
x = -2
y = 1
Answer:
x=2, y=4
Step-by-step explanation:
When using elimination, the objective is to elimate one variable. In this case, we see that "y" can easily be eliminated by adding the two equations together since you will get 3y + (-3y) which will eliminate y because the value would become 0, letting us solve for x.
Then we get
, because the y's will eliminated, and 8x+7x is 15x, and 28+2 is 30.
Then divide by 15 on both sides and you get x=2
If x=2, then we can substitute that value into any of the previous given equations and find the value of y.
8×2 +3y = 28
16+3y=28
3y=12
y=4
So the answer to your system of equations would be x=2, and y=4
You can substitute the answers we found to see that they satisfy the equation.
Hope this helped.
Answer:
60 miles per hour
Step-by-step explanation:
Consider the structure of the wording: "miles per hour"
The word "per" means for each. There is you clue.
Each is, one of and one of is unit measurement
So the controlling element in this question is that you need to convert the 3 hours into 1 hour.
Using ratio properties
180
3
=
x
miles
1
hour
We need to 'force' the left hand side into the same form as the right. That is: we need to convert the denominator into 1 and see what happens to the numerator.
⇒
180
÷
3
3
÷
3
=
x
1
⇒
60
1
=
x
1
So the unit rate of speed is
60
miles
per
−−−
hour
