LY = 5.2 , TY = 3.9
Δ LTN is a right triangle , ∠T = 90° , TY⊥LN
∴ TY² = LY * YN
∴ 3.9² = 5.2 * YN
∴ YN = 3.9²/5.2 = 2.925
∴ LN = LY + YN = 5.2 + 2.925 = 8.125
Δ LYT is a right triangle , ∠Y = 90°
LT² = LY² + YT² = 5.2² + 3.9² = 42.25
∴ LT = √42.25 = 6.5
Δ NYT is a right triangle , ∠Y = 90°
NT² = NY² + YT² = 2.925² + 3.9² = 23.765
∴ NT = √23.765 = 4.875
The preimeter of the rectangle LINT = 2 * (LT + TN)
= 2 * ( 6.5 + 4.875 )
= 2 * 11.375
= 22.75
An equation with a difference of 6 would be 12-6=6
X = pencils, y = pens
8x + 6y = 8.50
4x + 4y = 5.....multiply by -2
----------------
8x + 6y = 8.50
-8x - 8y = -10 (result of multiplying by -2)
-----------------add
-2y = - 1.50
y = -1.50 / -2
y = 0.75 <=== pens cost 0.75
4x + 4y = 5
4x + 4(0.75) = 5
4x + 3 = 5
4x = 5 - 3
4x = 2
x = 2/4
x = 0.50 <== pencils cost 0.50
