Question

find the value and explain​

Answer 1

Answer:

75

Step-by-step explanation:

x=5

y=8

5×8 + 7×5

40+35=75

Answer 2

$\LARGE\underline\textbf{SOLUTION :-}$

$\large\textsf{2x + 3y = 34......... ( i )}$

$\large\leadsto\textsf{ \cfrac{x + y }{ y } = \cfrac{13}{8} }$

$\large\textsf{8 ( x + y ) = 13 × y}$

$\large\textsf{8x + 8y = 13y}$

$\large\textsf{8x +8y - 13y = 0}$

$\large\textsf{8x - 5y = 0..... ( ii )}$

$\large\textsf{Multiple eq. ( i ) by 4 :-}$

$\large\textsf{4 ( 2x + 3y ) = 4 × 34}$

$\large\textsf{8x + 12y = 136..... ( iii )}$

$\large\textsf{Subtract eq. ( ii ) from ( iii ) :-}$

$\large\textsf{ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: 8x + 12y = 136} \\\large\textsf{( - ) 8x - 5y = 0} \\ \large\textsf{---------------------------------}$

$\large\textsf{ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: 17y = 136}\\ \large\textsf{\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: y = \cancel\cfrac{136}{17} }$

$\large\textsf{\colorbox{silver}{y = 8}}$

$\large\textsf{Substitute the value of y }\\ \large\textsf{in equation ( i )}$

$\large\textsf{2x + 3 × 8 = 35}$

$\large\textsf{2x + 11 = 35}$

$\large\textsf{2x = 35 - 11}$

$\large\textsf{x = \cancel\cfrac{24}{2} }$

$\large\textsf{\colorbox{silver}{x = 12}}$

$\large\textbf{So,}$

$\large\textsf{= 5y + 7x}$

$\large\textsf{= 5 × 8 + 7 × 12}$

$\large\textsf{= 40 + 84}$

$\large\textsf{= 124}$