Question

Solve by cross multiplication a) x+ 3y = 16 2x -y = 4​

Answer 1

Answer:

x = 4 and y = 4

it is given that,

⠀️️⠀️️️️⠀x + 3y = 16 ...(1)

⠀️️⠀️️️️ 2x - y = 4 ...(2)

we have to use cross multiplication method ( or Cramer's rule )

first write given equations in the standard form

i.e., ax + by + c = 0

x + 3y + (-16) = 0...(1)

2x + (-1)y + (-4) = 0 ...(2)

now applying rule,

x/{3 ×( -4) - (-16) × (-1)} = -y/{1 × (-4) - (-16) × 2}

= 1/{1×(-1) - 3 × 2 }

⇒x/(-12 - 16) = -y/(-4 + 32) = 1/(-1 - 6)

⇒x/-28 = -y/28 = 1/-7

so, x = -28/-7 = 4

y = -28/-7 = 4

hence, value of x = 4 and y = 4

$\: \:$

___________

hope this helps! <3

Answer 2

Step-by-step explanation:

Answer:-

Use elimination to solve:

L1 x+3y=16

L2 2x-y=4

Multiply L2 by 3 so that when you add L1+L2 the y's cancel so that you can solve for x.

L2 3(2x-y)=3(4) ---> 6x-3y=12

Now add this to L1:

x+3y=16

6x-3y=12

_________

7x+0=28

7x=28

7x/7=28/7

x=4

Now substitute 4 in for x in either L1 or L2 and solve for y, I'm going with L1:

(4)+3y=16

4+3y=16

4-4+3y=16-4

3y=12

3y/3=12/3

y=4

The solution (x,y) is (4,4)

Happy Calculating!!!

hope this helps you ☺️