The ounces of chocolate chips used by Mrs Jacob is 70 ounce
Solution:
Given that Jacob is making several batches of cookies and is using 84 total ounces of chips
Let "c" be the ounces of chocolate chips
Let "p" be the ounces of peanut butter chips
To find: ounces of chocolate chips used by Mrs Jacob
Given that There are 5 times as many ounces of chocolate chips as peanut butter chips
Thus we can frame a equation as:
ounces of chocolate chips = 5 x ounces of peanut butter chips
c = 5p -------- eqn 1
Jacob used 84 total ounces of chip. Therefore,
ounces of chocolate chips + ounces of peanut butter chips = 84
c + p = 84 ---- eqn 2
Substitute eqn 1 in eqn 2
5p + p = 84
6p = 84
p = 14
Substitute p = 14 in eqn 1
c = 5(14) = 70
c = 70
Thus the ounces of chocolate chips used by Mrs Jacob is 70 ounce