2x + 2y = 4 -x+ 2y = 4

x = 0, y = 2

Step-by-step explanation:

We can use substitution method to substitute 2y into 2x + 2y = 4.

-x + 2y = 4

2y = 4 + x --- Equation 1

2x + 2y = 4 --- Equation 2

Substitute Equation 1 into Equation 2:

2x + 2y = 4

2x + 4 + x = 4

3x + 4 = 4

Isolate 3x.

3x = 4-4

    = 0

Find x.

x = 0 ÷ 3

x = 0

Substitute x = 0 into Equation 1:

2y = 4 + x

2y = 4 + 0

    = 4

Find y.

y = 4 ÷ 2

y = 2

d

step-by-step explanation:

d

rick has $1400 and sally has $1500

step-by-step explanation:

to find amount of money rick has after 10 years :

principal = $1000 , time = 10 years , rate = 4% annually

to find amount of money sally has after 10 years :

her friend gives to pay her $50 per year, therefore money she has after 10 years = 50 × 10 = $500

also, sally gets $1000 after 10 years,

therefore, total amount of money sally has after 10 years = 500 + 1000 = $1500

so, after 10 years : rick has $1400 and sally has $1500