X − 4y = 7
5x + 9y = 6
5x − 20y = 35 //1st * 5
5x + 9y = 6
5x +9y - 5x + 20y = 6 - 35 //2nd - 1st
5x + 9y = 6
29y=-29
5x=6-9y
y=-1 //1st : 29
5x=6-9*(-1)
y=-1
x=15:5 //2nd : 5
y=-1
x=3
check:
for x=3 and y=-1 there is:
x − 4y = 7 is 3 − 4*(-1) = 7 is 7=7 ok
5x + 9y = 6 is 15-9=6 is 6=6 ok
answer: (3;-1) represents the solution.
Answer:
386
Step-by-step explanation:
Just do 300x1.4 because that gives you the extra 40% (the answer is £420 btws)
Hi There! I’m happy to help! Answer: $23.05
Step-by-step explanation:
First, since there is 3 shirts that cost $25.65, multiply them. Product is $76.95. Now, we subtract the $76.95 from the $100, making $23.05 her change. Hope this helps!
Answer:
Height of the building = 77 ft.
Step-by-step explanation:
Let the height of the building (AB) = h feet
It's given that height of a woman (ED) = 5 feet 3 inches
≈ 5 feet +
ft
≈ 5.25 ft
Length of the shadow (BC) of the building = 55 ft
Length of the shadow (DC) of the woman = 45 in ≈ 3.75 ft
Since, both the triangles ABC and EDC are similar, their corresponding sides will be proportional.
By the property of similar triangles,


h = 
h = 77 ft
Therefore, height of the building will be 77 ft.