Boys:girls = 4/5
boys = 4/(4+5) = 4/9 of the class
A) Height -7 = base
B) .5 * height * base = 60
Substituting A into B
B) .5 * height * (height -7) = 60
B) .5*height^2 -3.5*height = 60
B) .5*height^2 -3.5*height -60 = 0
Using the quadratic formula:
Height = 15
Subtracting 7 gives us the base length
Base = 8
**************************************************************
Double-Check
.5 * 15 * 8 = 60
Answer:
The correct option is D) 43 items.
Step-by-step explanation:
As we know that total given time is ,
,
Out of which cashier spends 40 seconds to process the customer's payment.
So the remaining time = (126 - 40) = 86 secs.
And the remaining time is used to scan the item and so that we can calculate here the no items scan is = (86 ÷ 2) = 43.
Therefore we can say that 43 items are being purchased.
You take the first equation and make a value for y. So 6x + y =7 change it to :
y = -6x + 7
Now in the second equation replace the “y” with -6x +7 this is what it means to use substitution method . Your combined equation will now be :
8x + 9(-6x + 7) =17
Now do distributive property and you get :
8x + -54x +63 =17
Now combine like terms ;
-46x +63 =17
-46x =-46
x = 1
Now replace 1 for X value and we can get the value of Y .
Y=1
X=1
