Answer:
D
Step-by-step explanation:
Given the 2 equations
4x + 8y = 21 → (1)
y = - 
x + 3 → (2)
Substitute y = - x + 3 into (1)
4x + 8(- x + 3 ) = 21 ← distribute parenthesis on left side
4x - 4x + 24 = 21 ( subtract 24 from both sides )
0 = - 3 ← not possible
This indicates the system has no solutions
X − 4y = 7
5x + 9y = 6
5x − 20y = 35 //1st * 5
5x + 9y = 6
5x +9y - 5x + 20y = 6 - 35 //2nd - 1st
5x + 9y = 6
29y=-29
5x=6-9y
y=-1 //1st : 29
5x=6-9*(-1)
y=-1
x=15:5 //2nd : 5
y=-1
x=3
check:
for x=3 and y=-1 there is:
x − 4y = 7 is 3 − 4*(-1) = 7 is 7=7 ok
5x + 9y = 6 is 15-9=6 is 6=6 ok
answer: (3;-1) represents the solution.
Answer:
24.99 cm
Step-by-step explanation:
We are provided with the radius of the circle so we can use that to solve for the circumference(perimeter) of the circle. The formula to solve for the circumference is 2*pi*r.
2*pi*7 = 14pi = 43.98 cm
Although this is the circumference of the entire circle... To solve for the circumference of a quarter-circle we must find the quarter of that:
43.98 * 1/4 = 10.99 cm
We are already provided with the other two sides, which are both equal to 7 cm since they are radii.
Perimeter = 10.99 +7 + 7 = 24.99 cm
Hope this helps!
Profit = paid - supplies
Plug in the given values. We are finding out how much money he needs per room, if he is doing 4 rooms, and subtracting the supplies: 300 = 4n - 4*32.50
Simplify: 300 = 4n - 130
Add 130 to each side. 430 = 4n
Divide by 4 on each side: 107.50= n
300 = 4(107.50) - 130? True
This tells us he must be paid $107.50 to make $300 exactly. Anything larger than $107.51 and up will make more than $300.
