Answer:
The solution of the system of the equation is (2, 2)
Step-by-step explanation:
Let us solve the system of equations
∵ 3x + y = 8 ⇒ (1)
∵ 3x - y = 4 ⇒ (2)
→ Add equations (1) and (2) to eliminate y
∴ (3x + 3x) + (y + -y) = (8 + 4)
∴ 6x + 0 = 12
∴ 6x = 12
→ Divide both sides by 6 to find x
∵ 
∴ x = 2
→ Substitute the value of x in equation (1) to find y
∵ 3(2) + y = 8
∴ 6 + y = 8
→ Subtract 6 from both sides
∵ 6 - 6 + y = 8 - 6
∴ y = 2
∴ The solution of the system of the equation is (2, 2)
At the beginning of year 6, that means 5 years only have elapsed, thus t = 5.

18 times 4 = 72
Because 5000 times 4 = 20,000
The change in temp. is -72degrees
Answer:
m∠QPR = 35° m∠QPM =40° m∠PRS = 30°
Step-by-step explanation:
ΔPRQ is a right triangle with right angle at R. So m∠QPR = 90 - 55 = 35
ΔQPM is a right triangle with right angle at M. So m∠QPM = 90 - 40 = 40
Arc RQ = 2(35) = 70 and arc SR = 2(25) = 50.
So arc PS = 180 - (arc RQ + arc SR) = 180 - (70 + 50) = 180 - 120 = 60
Now arc PS is the intercepted arc for ∠PRS.
Therefore, m∠PRS = 60/2 = 30
I used the fact that an inscribed angle has a measure 1/2 the measure of the intercepted arc several times. Also, I used the fact that the acute angles of a right triangle are complementary. And, finally I used the fact that an inscribed angle in a semicircle is a right angle.
I hope this helped.