Question 847266
Let {{{ x }}} = cups of olive oil she should add
{{{ x + 1 }}} will be the cups of oil in vinaigrette
{{{ 3 + x + 1 =x + 4 }}} is the total cups in recipe
I can say:
{{{ 3 / ( x + 4 ) = .25 }}}
{{{ 3 = .25*( x + 4 ) }}}
{{{ 3 = .25x + 1 }}}
{{{ .25x = 2 }}}
{{{ x =8 }}}
She needs to add 8 cups of oil
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Let {{{ C }}} = total cost
You need to know { ounces / cup ). When you
have that, make the conversions:
cost of oil: ( 40 cents / ounce ) x ( ounces / cup ) x ( 9 cups ) = cents
cost of vinegar: ( 25 cents / ounce ) x ( ounces / cup ) x ( 3 cups ) = cents
Add them to find {{{ C }}}, total cost