Question

#9 and #10 Please show work

Answer 1

Answer:

Part 9) The number of items on Emily's grocery list is 5 and the number of items on Bobby's grocery list is 13

Part 10) The height of the taller bookshelf is 4 feet and the height of the shorter bookshelf is 1 foot

Step-by-step explanation:

Part 9)

Let

x ----> number of items on Emily's grocery list

x ----> number of items on Bobby's grocery list

we know that

$y=2x+3$ ----> equation A

$x=y-8$ ----> equation B

Solve by substitution

Substitute equation A in equation B

$x=(2x+3)-8$

solve for x

$x=2x-5$

$2x-x=5$

$x=5$

Find the value of y

$y=2(5)+3=13$

therefore

The number of items on Emily's grocery list is 5 and the number of items on Bobby's grocery list is 13

Part 10)

Let

x ----> the height of the taller bookshelf in feet

y ----> the height of the shorter bookshelf in feet

we have

$x=5y-1$ ----> equation A

Remember that

$1\ ft=12\ in$

To convert inches to feet divide by 12

so

$60\ in=60/12=5\ ft$

$x+y=5$ ----> equation B

Solve the system by substitution

substitute equation A in equation B

$(5y-1)+y=5$

solve for y

$5y+y=5+1$

$6y=6$

$y=1\ ft$

Find the value of x

$x=5(1)-1=4\ ft$

therefore

The height of the taller bookshelf is 4 feet and the height of the shorter bookshelf is 1 foot