Thread: Problem solving with algerbra

Hey. For a common test tomorrow I need to know how to work out (algerbraicly) how to do these type of problem solving questions.
If anyone could help it would be much appreciated.

Silvio is 10 years older than Bonita. The sum of their ages is 4 times Bonita's age. What is their ages?

From what I can understand:
Silvio: Silvio = Bonita + 10
Bonitia: Bonita = Bonita
Sum: 4 x Bonita

Thanks,
Adrian

Use the first letters of the names for brevity. You correctly wrote the first equation: S = B + 10. Now express the following two quantity through S and B:

(1) the sum of the ages of Silvio and Bonita;
(2) 4 times Bonita's age.

Equate these quantities to get the second equation in B and S. Then solve this system of two equations.

1. Silvio = Bonita + 10
2. Sum (Silvio + Bonita) = 4 x Bonita

Let say Silvio=y and Bonita=x

Then we will have 2 equations;
1. Silvio = Bonita + 10
y = x + 10

2. Sum (Silvio + Bonita) = 4 x Bonita
y + x = 4x

so you can substitute eq (1.) into eq (2.) to find the value of x.

y + x = 4x
(x + 10) + x = 4x
x = ?

once you have the value of x, you can proceed to find the value of y by putting the value of x into either eq (1.) or eq (2.).

remember that x and y is representing of Silvio and Bonita age.

the answer should be;
Silvio is 15 years old
Bonita is 5 years old

Cheers mate....