Question

Solve it by using cross multiplication method

x + y = 14
x - y = 4

No Spam​

Answer 1

Answer:

$\mathtt\green{LET:-}$

$\mathtt{a1 = 1 \: \: \: \: \: \: \: \: \: \: b1 = 1 \: \: \: \: \: \: \: \: \: c1 = - 14}$

$\mathtt{a2 = - 1 \: \: \: \: \: \: \: b2 = - 1 \: \: \: \: \: c2 = - 4}$

$\: \: \: \: \: \: \: \: \: \: \: \: \:$

$\mathtt{ \frac{x}{b1c2 - b2c1} = \frac{y}{c1a2 - c2a1} = \frac{1}{a1b2 - a2b1} }$

$\: \: \: \: \: \: \: \: \: \: \: \: \:$

$\mathtt\green{BY \: USING \: RULE \: (FORMULA)}$

$\mathtt{ \frac{x}{( - 1)( - 4) - ( - 1)( - 14)} = \frac{y}{( - 14)(1) - ( - 4)(1)} = \frac{1}{(1)( - 1) - (1)(1)} }$

$\mathtt{ \frac{x}{ - 4 - 14} = \frac{y}{( - 14) + 4} = \frac{1}{ - 1 - 1} }$

$\mathtt{ \frac{x}{ - 18} = \frac{y}{ - 10} = \frac{1}{ - 2} }$

$\mathtt{x = \frac{ - 18}{ - 2} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: y = \frac{ - 10}{ - 2} }$

$\mathtt{x = 9 \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: y = 5}$

$\fbox\green{x=9}$

$\fbox\green{y=5}$

Answer 2

Answer:

LET:−

\mathtt{a1 = 1 \: \: \: \: \: \: \: \: \: \: b1 = 1 \: \: \: \: \: \: \: \: \: c1 = - 14}a1=1b1=1c1=−14

\mathtt{a2 = - 1 \: \: \: \: \: \: \: b2 = - 1 \: \: \: \: \: c2 = - 4}a2=−1b2=−1c2=−4

\: \: \: \: \: \: \: \: \: \: \: \: \:

\mathtt{ \frac{x}{b1c2 - b2c1} = \frac{y}{c1a2 - c2a1} = \frac{1}{a1b2 - a2b1} }

b1c2−b2c1

x

=

c1a2−c2a1

y

=

a1b2−a2b1

1

\: \: \: \: \: \: \: \: \: \: \: \: \:

\mathtt\green{BY \: USING \: RULE \: (FORMULA)}BYUSINGRULE(FORMULA)

\mathtt{ \frac{x}{( - 1)( - 4) - ( - 1)( - 14)} = \frac{y}{( - 14)(1) - ( - 4)(1)} = \frac{1}{(1)( - 1) - (1)(1)} }

(−1)(−4)−(−1)(−14)

x

=

(−14)(1)−(−4)(1)

y

=

(1)(−1)−(1)(1)

1

\mathtt{ \frac{x}{ - 4 - 14} = \frac{y}{( - 14) + 4} = \frac{1}{ - 1 - 1} }

−4−14

x

=

(−14)+4

y

=

−1−1

1

\mathtt{ \frac{x}{ - 18} = \frac{y}{ - 10} = \frac{1}{ - 2} }

−18

x

=

−10

y

=

−2

1

\mathtt{x = \frac{ - 18}{ - 2} \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: y = \frac{ - 10}{ - 2} }x=

−2

−18

y=

−2

−10

\mathtt{x = 9 \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: y = 5}x=9y=5

\fbox\green{x=9}

x=9

\fbox\green{y=5}

y=5