let h= history books
science books = s
h=2s there are 2 times as many history as science so to get them equal we double the science
h+s=81 there are 81 total history and science books
2s+s=81 substitute 2s for h in the above equation
3s = 81 combine like terms
s = 27
There are 27 science books
h=2s
h=2(27)
h=54
there are 54 history books
Answer:75+5.5x equal or greater than 130
Step-by-step explanation:
So the circle is 39.25
And the area of triangle 30 together about 39.25