find the value and explain
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find the value and explain
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Verified answer
Answer:
75
Step-by-step explanation:
x=5
y=8
5×8 + 7×5
40+35=75
[tex]\LARGE\underline\textbf{SOLUTION :-}[/tex]
[tex]\large\textsf{2x + 3y = 34......... ( i )}[/tex]
[tex]\large\leadsto\textsf{$\cfrac{x + y }{ y } = \cfrac{13}{8}$}[/tex]
[tex]\large\textsf{8 ( x + y ) = 13 × y}[/tex]
[tex]\large\textsf{8x + 8y = 13y}[/tex]
[tex]\large\textsf{8x +8y - 13y = 0}[/tex]
[tex]\large\textsf{8x - 5y = 0..... ( ii )}[/tex]
[tex]\large\textsf{Multiple eq. ( i ) by 4 :-}[/tex]
[tex]\large\textsf{4 ( 2x + 3y ) = 4 × 34}[/tex]
[tex]\large\textsf{8x + 12y = 136..... ( iii )}[/tex]
[tex]\large\textsf{Subtract eq. ( ii ) from ( iii ) :-}[/tex]
[tex]\large\textsf{ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: 8x + 12y = 136} \\\large\textsf{( - ) 8x - 5y = 0} \\ \large\textsf{---------------------------------}[/tex]
[tex]\large\textsf{ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: 17y = 136}\\ \large\textsf{\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: y = $\cancel\cfrac{136}{17}$}[/tex]
[tex]\large\textsf{\colorbox{silver}{y = 8}}[/tex]
[tex]\large\textsf{Substitute the value of y }\\ \large\textsf{in equation ( i )}[/tex]
[tex]\large\textsf{2x + 3 × 8 = 35}[/tex]
[tex]\large\textsf{2x + 11 = 35}[/tex]
[tex]\large\textsf{2x = 35 - 11}[/tex]
[tex]\large\textsf{x = $ \cancel\cfrac{24}{2}$}[/tex]
[tex]\large\textsf{\colorbox{silver}{x = 12}}[/tex]
[tex]\large\textbf{So,}[/tex]
[tex]\large\textsf{= 5y + 7x}[/tex]
[tex]\large\textsf{= 5 × 8 + 7 × 12}[/tex]
[tex]\large\textsf{= 40 + 84}[/tex]
[tex]\large\textsf{= 124}[/tex]