Answer:
Option C
Step-by-step explanation:
we have
x+2y=2 ------> equation A
-4x+4y=-8 ------> equation B
Multiply equation B by -1 both sides
-1(-4x+4y)=-8*(-1)
4x-4y=8 -----> equation C
Adds equation A and equation C
x+2y=2
4x-4y=8
--------------
5x-2y=10 ----> equation D
An equivalent system of equations is equation A and equation D
so
x+2y=2 ------> equation A
5x-2y=10 ----> equation D
Answer:
Charlotte's age = 10 years and Robert's age = 2(10) = 20 years
Step-by-step explanation:
Let Robert's age is r and Charlotte's age is c.
r = 2c
Five years ago,
Robert's age = (r-5)
His age was three times Charlotte's age. So,
(r-5) = 3(c-5)
Put r = 2c in the above equation. So,
(2c-5) = 3(c-5)
(2c-5) = 3c-15
Taking like terms together,
15-5 = 3c-2c
c = 10
So, Charlotte's age = 10 years
Robert's age = 2(10) = 20 years
Answer:
mean and range
Step-by-step explanation: