Colin invests £4000 into his bank account. He receives 5% per year simple interest.
How much will Colin have after 3 years?

4,600

Step-by-step explanation:

A = P(1 + rt)

P = 4000

r = 0.05 (rate in percent form)

t = 3 years

A = 4000(1 + (0.05)(3))

A = 4000(1+0.15)

A = 4000(1.15)

A = 4,600

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.