Question

How do I solve these questions?

Answer 1

Function rule:  a = 20w + 115

Slope: 20

Initial value: 115

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We start with $115 in the account. This is the initial value. Each week we add on $20.

So we add $20 for 1 week

We add 2*20 = $40 for 2 weeks

We add 3*20 = $60 for 3 weeks

etc etc

In general, we add 20*w dollars for w weeks onto 115 to get a = 20w+115

The slope is 20 because this is the rate of change, ie how fast the account grows. It grows 20 dollars per week.