Question

if 9x2_4y2=80 and 3x+2y=20 then find 3x-2y​

Answer 1

Answer:

4

Step-by-step explanation:

$9 {x}^{2} - 4 {y}^{2} = 80$

$= > ( {3x)}^{2} - {(2y)}^{2} = 80$

$= > (3x + 2y)(3x - 2y) = 80$

Because a²-b²=(a+b)(a-b)

It's given,

$3x + 2y = 20$

Therefore,

$= > 20(3x - 2y) = 80$

$= > 3x - 2y = 4$

Hence, your answer is 4.

Answer 2

Answer:

• 3x-2y=4

Step-by-step explanation:

given

• 9x²-4y²=80

this form can be written as

• (3x)²-(2y)²=80
• (3x-2y)(3x+2y)=80       (1)   /// a²-b²=(a-b)(a+b)

given also

 put in  3x+2y=20 in equation 1

• (3x-2y)(20)=80
• 3x-2y=80/20
• 3x-2y=4 is the answer