Hi there!
We can set up a systems of equation from this situation.
paperback books : x
hard-covered books : y
They sold total of 89 books.
x + y = 89
The library raised $271.
2.00x + 5.00y = 271
which can be rewritten as...
2x + 5y = 271
So we got
x + y = 89
2x + 5y = 271
Using substitution method would be easier than elimination for this equations.
Since we have to find out the number of hard-covered books, let's get rid of x.
Make the first equation to be x = 89 - y.
x = 89 - y
2x + 5y = 271
2 (89 - y) + 5y = 271
178 - 2y + 5y = 271
3y = 93
y = 31
The library sold 31 hard-covered books.
Hope this helped! :)
It is closer to half because 6/12 is half
Answer:
a=90⁰
b=40⁰
c=140
d=40⁰
Step-by-step explanation:
<em><u>Main</u></em><em><u> </u></em><em><u>princip</u></em><em><u>le</u></em>
Achieve 180⁰ on every line
<em><u>a </u></em><em><u> </u></em> was achieved by virtue of the 90⁰ symbol
b = a+ 50⁰(90⁰+50⁰-180)
c=a+50⁰(vertically opposite angle) if you need some help,a=90⁰ (already explained above).
d=b(vertically opposite angle)
just so you understand the concept especially that of vertically opposite angles (b is vertically opposite d and therefore are equal so no calculations needed there, in the case of c, two angles when put together are opposite c so they have to be summed up and the sum is equal to angle <em>c</em>.
Think of it as an infinity loop the two angles facing each other are the same
<em><u>OR</u></em>
like the "x" symbol every angle is equal to angle direct opposite to it.
<em><u>Note</u></em><em><u>:</u></em> Don't get confused with opposite and adjacent.