Question 1161277
<pre>
                    PRICE       MASS       COST

raisins             4.2        10-x       4.2(10-x)

dried fruit         6.9         x         6.9x

MIXTURE            5.28        10        5.28*10
</pre>
Equate the costs.
{{{4.2(10-x)+6.9x=52.8}}}
Simplify and solve for x.






-----------All In Variables Only---------------

KNOWN VARIABLES, GIVEN:  R, F, T, M
UNKNOWN VARIABLE:  x
<pre>
                    PRICE       MASS       COST

raisins             R          M-x        R(M-x)

dried fruit         F           x         Fx

MIXTURE            T            M          MT
</pre>
{{{highlight_green(R(M-x)+Fx=MT)}}}

{{{RM-Rx+Fx=MT}}}

{{{Fx-Rx=MT-RM}}}

{{{(F-R)x=M(T-R)}}}

{{{highlight(x=M((T-R)/(F-R)))}}}