Answer:
(5, 3 ) and (- 
, - 10 )
Step-by-step explanation:
Given the 2 equations
2x - y = 7 → (1)
xy = 15 → (2)
Rearrange (1) expressing y in terms of x , that is
y = 2x - 7 → (3)
Substitute y = 2x - 7 into (2)
x(2x - 7) = 15
2x² - 7x = 15 ( subtract 15 from both sides )
2x² - 7x - 15 = 0 ← in standard form
(x - 5)(2x + 3) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 5 = 0 ⇒ x = 5
2x + 3 = 0 ⇒ 2x = - 3 ⇒ x = -
Substitute these values into (3) for corresponding values of y
x = 5 : y = 2(5) - 7 = 10 - 7 = 3 ⇒ (5, 3 )
x = - : y = 2(- ) - 7 = - 3 - 7 = - 10 ⇒ (- , - 10 )
6: 1,3,2,6
7: 1,7
Factors of 6 are 1,3,2,6 because 1x6 (6x1) and 3x2. (2x3)
Factors of 7 are 1,7 because seven is a odd number so you can only multiply it by one and itself. (1x7 or 7x1)
A=pie×radius squared is the area formula of a circle. The circumference formula or a circle is C=pie×diameter. 615.75=(3.14)(radius) squared. Divide both sides by the 3.14. What ever 615.75 divided by 3.14 is-is radius squared. The square root is your radius. The radius is half the diameter, so double what you have right now as the radius to get the diameter. Now since C=pie×diameter, your circumference is your pie×your diameter. Whatever your answer is-is your circumference.
