Question

Find the value of expression
$(3x - 5y) {}^{2}$
for x=3 and y=-1​

Answer 1

Answer:

IF X=3 AND Y=(-1)

=THEN,

=(3x - 5y)^2

=3×(3) - 5×(-1)

=9-(-5)

=-4^2

=16

Answer 2

$\bold {Given:-} \begin{cases} \sf{x = 3.} \\ \sf{y = - 1.} \end{cases}$

${ \large {\underline{Solution:-}}}$

${(3x - 5y) }^{2} \\ \\ \longrightarrow \: {(3x)}^{2} + {(5y)}^{2} - 2(3x)(5y). \\ \\ \longrightarrow \: {9x}^{2} + {25y}^{2} - 30xy.$

°•° Putting the Value of x = 3. and y = -1.

$\longrightarrow \: 9 {(3)}^{2} + 25 {( - 1)}^{2} - 30(3)( - 1). \\ \\ \longrightarrow \: 81 + 25 + 90. \\ \\ \longrightarrow \: 196.$

Our Answer will be.

$\longrightarrow{\huge {\underline {\boxed{196}}}}$