Question

Liz and Sara are making cookies for a bake sale. The graph shows the number of cookies that Liz bakes during a 5-hour period.

Answer 1

Statements

case A) Sara had baked more cookies at the start of the $5$ hours than Liz

The statement is True

we know that

At the start of the $5$ hours Liz has baked $220$ cookies-----> see the graph

Find the number of cookies that Sara has baked for $x=5$ hours

$y=45x+38$

$y=45*5+38=263$

$263 > 220$

therefore

Sara had baked more cookies at the start of the $5$ hours than Liz

case B) Sara bakes $45$ cookies each hour

The statement is True

we know that

The number of cookies baked each hour is equal to the slope of the linear equation

The linear equation is

$y=45x+38$

The slope is $m=45\frac{cookies}{hour}$

case C) Liz bakes $19$ cookies each hour

The statement is false

Find the slope of the Liz graph

The slope is equal to

$m=\frac{y2-y1}{x2-x1}$

Let

$A(0,19)\ B(4,179)$

Substitute the values

$m=\frac{179-19}{4-0}$

$m=40\frac{cookies}{hour}$

case D) Liz bakes more cookies each hour than Sara

The statement is False

Sara bakes $45$ cookies each hour

Liz bakes $40$ cookies each hour