Answer
$x=\frac{30}{4}=3\frac{3}{4}$c
Work Step by Step
Let x = cups of strawberries
Jim uses 3 cups of peaches to yield 4 jars of peach jam: $\frac{3}{4} $
He uses equal amounts of strawberries and peaches to make strawberry - peach jam:
$\frac{3}{4}=\frac{x}{10}$
$30=4x$
$x=\frac{30}{4}=3\frac{3}{4}$c
