X*80+y*60= 50*74
x +y =50 | * ( -60)

80x + 60y= 50*74
-60x - 60y=-50*60
---------------------------
20x= 50*(74-60)=50*14
x=50*14/20=35 pounds of 80 cents tea
y=50-35=15 pounds of 60 cents tea

8 0

3 years ago

If you were to use the substitution method to solve the following system, choose the new equation after the expression equivalen

stellarik [79]

If you were to use the substitution method to solve the following system, we need to write one of the equation to an expression equivalent to y. Let us say the second equation, we write it as follows:

6x – 3y = –3
-3y = -6x - 3
y = 2x + 1

We substitute the equation to the first given equation as follows:

2x – 5y = –3
2x – 5(2x + 1) = –3
2x - 10x - 5 = -3
-8x = 2
x = -1/4
y = 2(-1/4) + 1 = 1/2

4 0

3 years ago

An observer (O) spots a plane flying at a 42° angle to his horizontal line of sight. If the plane is flying at an altitude of 15

NeTakaya

Answer:

D. 22,417 feet

Step-by-step explanation:

Fine the diagram in the attachment for proper elucidation. Using the SOH, CAH, TOA trigonometry identity to solve for the distance (x) from the plane (P) to the observer (O), the longest side x is the hypotenuse and the side facing the angle of elevation is the opposite.

Hypotenuse = x and Opposite = 15,000feet

According to SOH;

$sin 42^0 = \frac{Opposite}{Hypotenuse} \\\\Sin42^0 = \frac{15000}{x}\\ \\x = \frac{15000}{sin42^0}\\\\ \\$

$x = \frac{15000}{ 0.6691} \\\\x = 22,417 feet$

Hence the distance (x) from the plane P to the observer O is approximately 22,417 feet

3 0

4 years ago