If one store sells 12 pens for $9.00 and another sells 10 pens for $7.80, which is the better deal? if you have to buy 120 pens, how much will you save by using the less expensive supplier? compare prices per pen

Hi there!

Shop 1.
12 pens equals $9.00
1 pen equals $9.00 / 12 = $0.75
120 pens equals $0.75 × 120 = $90.00

Shop 2.
10 pens equals $7.80
1 pen equals $7.80 / 10 = $0.78
120 pens equals $0.78 × 120 = $93.60

Therefore shop 1 is the cheapest shop and offers the best deal. When buying 120 pens the second shop is $3.60 more expensive.

4(x – 3) + 4 < 10 + 6x
Distribute the 4 on the left side.

4x -12 +4 < 10 + 6x
Combine like terms on the left side.

4x-8<10 +6x
Subtract the 6x from both sides.

-2x -8<10
Add the 8.

-2x <18
Divide by -2 & flip the inequality symbol (it's a math rule which states that if you multiply or divide by a negative, you must flip the inequality symbol).

x> -9

That's your final answer.