Answer:
D) Only (-1,9) is a solution.
Step-by-step explanation:
x+y =8
x^2 + y = 10
Lets check the first point (-1,9)
Put in x =-1 y =9
x+y =8
-1+9 = 8
8 =8
This works
x^2 + y = 10
(-1)^2 +9 =10
1+9 = 10
10 = 10
This works
Lets check the second point (-2,6)
Put in x =-2 y =6
x+y =8
-2+6 = 8
4=8
This does not work
We can stop now. (-2,6) cannot be a solution
We are going to make simultaneous equations.
x will be our $3 ice cream and y will be our $5 ice cream
Equation1 ---- x + y = 50 (the sum of all the ice creams they sell)
Equation 2 ---- 3x + 5y = 180 Sum of all the $3 and $5 ice creams is $180
Since we can't solve for both variables we will put one of the variables in terms of the other.
Take x+y=50 and subtract y from both sides. (I could have done subtracted x - it did not matter). Now we have x= ₋ y +50 (negative y +50)
Now I am going to take equation 2 and replace the x with -y +50
3 (-y +50) + 5y = 180
Now I will use the distributive law on the 3 and what's in the parentheses:
-3y + 150 + 5y = 180
Now I will combine like terms (the -3y and the 5y)
2y + 150 = 180
Now subtract 150 from both sides of the equation
2y = 30
Divide both sides by 2
and get y= 15 They sold 15 ice creams that cost $5 each
Since equation 1 is x+y=50 we can replace y with 15
x + 15 = 50 Now subtract 15 from both sides x = 35
Since x represents the $3 ice creams, they sold 35 of those.
Check:
35 X 3 = $105
15 x 5 = + <u>75
</u> $180
Answer:
The cellphone towers height is 1020 ft.
Step-by-step explanation:
This question is solved using proportions, by a rule of three.
A 10-ft post casts a 14-inch shadow.
Each feet has 12 inches, which means that a post with 10 feet will cast a 14/12 = 1.167 ft shadow. How tall is the cell-phone tower with a 119-feet shadow?
10 feet post - 1.167 ft shadow
x feet tower - 119 feet shadow
Applying cross multiplication:
The cellphone towers height is 1020 ft.
Answer:
12 miles
Step-by-step explanation:
30-6=24
24/2=12 miles
Answer:
1.4
Step-by-step explanation:
