In 1974 a mother was 6 times as old as her daughter. If the mother turned 50 in the year 2000, in what year was the mother double her daughter’s age? This is in the topic of linear equations and please provide an explanation. (The working out)

1990

Step-by-step explanation:

Since the mother was 50 years old in 2000, she was 50 - (2000-1974) = 50 - 26 = 24 years old in 1974.

Hence, the daughter was 24/6 = 4 years old in 1974.

In "x" years after 1974, the daughter will be 4+x years old, while the mother will be 24+x years old.

We need to find "x" from the equation

2(4 + x) = 24+x.

8 + 2x = 24 + x,

x = 24 - 8 = 16.

1974 + 16 = 1990.

Answer In 1990 the mother doubles her daughter's age

Check In 1990 mother's age is/was 24 + 16 = 40 years.

In 1990 the daughter's age is/was 4 + 16 = 20 years.

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15