X=12, y=7.5
Here is an explanation if you want to know how to do it:
First, look at the diagram and think about what you know so far. Since the lines are parallel, 5x+4y and 12y must be equal. We also know that there is a right angle, so since both angles are equal, 12y=90 and 5x+4y=90.
Solve for y by dividing 90 by 12 to get 7.5, so y=7.5. Sub in this value to the equation on top and you should get 5x+4(7.5)=90 4(7.5)=30, so subtract that from 90 to get 60 and divide 60 by 5 to get 12, so x=12.
Answer:
n = -4
Step-by-step explanation:
2 - 1/2 n = 3n + 16
Combine the constants by subtracting 2 from both sides.
-1/2n = 3n + 14
Combine the variable by subtracting 3n from both sides.
-7/2n = 14
Multiply both sides by 2 to simplify the fraction.
-7n = 28
Isolate n by dividing by -7 on both sides.
n = -4
Check.
2 - 1/2(-4) = 3(-4) + 16
2 + 2 = -12 + 16
4 = 4
Your answer is correct.
Standard form is ax+by=c
mnus 7y both sides
6x-7y=0
Answer:
4d+2m+13
Step-by-step explanation:
Answer:
Roy is 10 years old at present and Joan is 5 years old at present
Step-by-step explanation:
Let
x----> Roy's age
y----> Joan's age
we know that
x=2y ----> equation A
(x+3)+(y+3)=21 ----> equation B
substitute equation A in equation B
(2y+3)+(y+3)=21
solve for y
3y+6=21
3y=21-6
3y=15
y=5 years
Find the value of x
x=2y ----> x=2(5)=10 years
therefore
Roy is 10 years old at present
Joan is 5 years old at present