John is twice as old as Mary. The sum of their ages is 21. How old is Mary?
1 answer:
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The complete question in the attached figure
Let
x-----------------> number of <span>paintbrushes----------- > $0.95 each
y---------------- > number of jar of paint-------------- > $0.99 each
we know that
0.95x+0.99y = </span><span>$4.87
</span><span>
using a graph tool
</span>the solution will be a pair of coordinates that are whole numbers -- > see the attached figure
<span>
the solution is the point (2,3)
x=2---------------------- > </span>number of paintbrushes
y=3---------------------- > number of jar of paint
the answer is
number of paintbrushes=2
number of jar of paint=3<span>
</span>
Let
x-----------------> number of <span>paintbrushes----------- > $0.95 each
y---------------- > number of jar of paint-------------- > $0.99 each
we know that
0.95x+0.99y = </span><span>$4.87
</span><span>
using a graph tool
</span>the solution will be a pair of coordinates that are whole numbers -- > see the attached figure
<span>
the solution is the point (2,3)
x=2---------------------- > </span>number of paintbrushes
y=3---------------------- > number of jar of paint
the answer is
number of paintbrushes=2
number of jar of paint=3<span>
</span>