7. The sun is at an angle of elevation of 58º. A tree casts a shadow 20 meters long onthe ground. How tall is the tree?

Answer:

x=5, y=8. (5, 8).

Step-by-step explanation:

3x+5y=55

5x+4y=57

---------------

5(3x+5y)=5(55)

-3(5x+4y)=-3(57)

-------------------------

15x+25y=275

-15x-12y=-171

---------------------

13y=104

y=104/13

y=8

3x+5(8)=55

3x+40=55

3x=55-40

3x=15

x=15/3

x=5

Answer:

10/12

Step-by-step explanation:

-2x because you are taking away 4-6x and the variable is x

Answer:

a) 1/9 quarts

b) 1/3 quarts

Step-by-step explanation:

Gordon pours 4/9 quarts of milk from a pitcher equally into 4 mugs.

a. Find the amount of milk in each mug.

To solve the first part of this question, we can simply use the idea of proportion;

Let x be the amount of milk in 1 mug

4/9  quarts  =   4 mugs

   x               =    1  mugs

We will cross multiply

4x  =  4/9

To get the value of x, we will divide both-side of the equation by 4

4x/ 4  =   4/9 ÷  4

(on the left hand- side of the equation, 4 will divide 4 leaving us with x)

x  =  4/9 ÷  4

( This ÷4 can be change to become × 1/4)

x  =   4/9   ×   1/4

(The 4 at the numerator will cancel out the 4 at the denominator leaving us with 1/9)

x  =  1/9

Therefore the amount  of milk in  each mug is 1/9 quart

b.Find the amount of milk in 3 mugs

For this second part of the question, we can also use proportion to solve;

Let x be the amount of milk in 3 mugs

4/9 quarts = 4 mugs

 x               = 3 mugs

Cross multiply

4x  =   3  ×  4/9

(At the right-hand side of this equation 3 can divide 9 which will give us 3 )

4x   =   1 × 4 /3

4x  = 4/3

We can now divide both-side of the equation by 4 to get the value of x

4x/4  = 4/3  ÷  4

(On the left hand side of the equation, 4 will cancel out 4 leaving us with just x and on the right-hand side of the equation ÷  4 can be changed to ×1/4)

x   =  4/3  ×  1/4

(4 will cancel 4 leaving us with  1/3)

x =  1/3

Therefore the amount of milk in 3 mugs is 1/3 quarts