We know that
• The first brand is 45% pure.
,• The second brand is 70% pure.
,• They want to obtain 60 gallons with a 65% pure.
Let's call x the amount of 70% antifreeze.
Based on the given information, we can express the following.
[tex]0.7x+0.45\mleft(60-x\mright)=0.65(60)[/tex]0.7x represents a 70% antifreeze. The second term represents 45% antifreeze, and 0.65(60) represents the final product. Let's solve for x.
[tex]\begin{gathered} \text{0}.7x+27-0.45x=39 \\ 0.25x=39-27 \\ 0.25x=12 \\ x=\frac{12}{0.25} \\ x=48 \end{gathered}[/tex]Because 60-48 = 12.