Question

I just need the last 2. I don't understand what the last 2 r asking for​

Answer 1

Question 3
Equation for Malik:
y = 350 + 7x

Equation for Saraiah:
y = 400 + 4x

Question 4
Both of them will have the same amount of money after
50/3 years
or
16 2/3 years
or
16 years 8 months

Explanation:

• Malik's interest rate as decimal = 2/100 = 0.02

• Saraiah's interest rate as decimal = 1/100 = 0.01

• The formula for simple interest is given as
  I = P r t\

• The total amount earned including interest
  = Principal + Interest
  = P + P · r · t
  = P(1 + r · t)

• We are asked to use y for the total amount and x for the number of years

• In terms of y = total amount and x = number of years:
  y = P(1 + r · x)

#3

Amount in Malik's account after x years given 2% interest
y = 350(1 + 0.02x)
y = 350 + 7x

For Saraiah's account:
y = 400(1 + 0.01x)
y = 400 + 4x

#4

If both Malik and Saraiah have the same amount of money after x years, then the right side of both their equations must be equal

Therefore

`350+7x = 400+4x\\\\\mathrm{Move}\:350\:\mathrm{to\:the\:right\:side \:by \:subtracting\: 350 \:from\:both\: sides}\\350+7x-350=400+4x-350\\\\\mathrm{Simplify}\\7x=4x+50\\\\`

`\mathrm{Subtract\:}4x\mathrm{\:from\:both\:sides}\\\\7x-4x=4x+50-4x\\3x=50\\\\\mathrm{Divide\:both\:sides\:by\:}3\\\\(3x)/(3)=(50)/(3)\\\\x=(50)/(3)`

Therefore both of them will have the same amount of money after
`(50)/(3)` years which is
`{16(2)/(3)` years

2/3 year = 2/3 x 12 months = 8 months

So both of them will have the same amount of money after
`{16(2)/(3)` years or 16 years and 8 months