f(x) = -2x-3 and g(x) = x^2+5x then calculate f(2)+g(1)

We store the definition:

f (x) = - 2 x - 3

We store the definition:

g (x) = x^{2} + 5 x

Applying the definitions,

f (2) + g (1)

becomes

- 2 \times 2

- 3

+ 1^{2}

+ 5 \times 1

Let's evaluate:

- 2 \times 2

- 3

+ 1^{2}

+ 5 \times 1

ⓘ Multiplications are done before additions and subtractions:

2 \times 2

4

■Start from

-3

and move forward

1

on the number line, getting closer to zero:

- 3 + 1

-2

- 4 - 2 + 5

ⓘ Start from

-4

and move back

2

more on the number line, away from zero:

- 4 - 2

-6

- 6 + 5

ⓘ Start from

-6

and move forward

5

on the number line, getting closer to zero:

- 6 + 5

-1

▶Result:

-1