Solve the problem using matrices.
-Jerry has three pieces of string. The total length is $80 \mathrm {~cm}$. The sum of the two longer pieces is $69 \mathrm {~cm}$. The middle piece is twice as long as the shortest piece. What are the lengths of the three pieces?
A) $5.5 \mathrm {~cm} ; 11 \mathrm {~cm} ; 63.5 \mathrm {~cm}$
B) $11 \mathrm {~cm} ; 47 \mathrm {~cm} ; 57 \mathrm {~cm}$
C) No solution
D) $11 \mathrm {~cm} ; 22 \mathrm {~cm} ; 47 \mathrm {~cm}$

Question

Quizplus · Accepted Answer

Let the lengths of the three pieces be $x$, $2x$, and $y$, respectively, with $x$ being the shortest piece and $y$ the longest. The equations based on the problem statement are: $x + 2x + y = 80$ and $2x + y = 69$. Solving these equations gives $x = 11$, $2x = 22$, and $y = 47$.

Solve the Problem Using Matrices 80 cm80 \mathrm {~cm}80 cm the Sum of the Two Longer Pieces Is

Solve the Problem Using Matrices $80 \mathrm {~cm}$ the Sum of the Two Longer Pieces Is