First you have to find the area of the rectangular grid. The area of a rectangle is length•width.
So:
A= 20•12
A= 240cm
Then you need to convert 240cm into mm.
240cm is 2400mm.
Then you need to figure out how many triangles can fit into the rectangle if all the triangles have an area of 25mm. So you divide 2400 by 25.
2400:25= 96
So Alex can fit 96 triangles into the grid.
1)
x+10<-7
bring 10 to the other side
x<-10-7
x<-17
2)
-3x-4>5
bring -4 to the other side
-3x>9
divide -3 at the other side, since it is negative it changes to less than
x<-3
If the triangles are congruents:
1) AC must be congruent with FE→AC=FE→y+3=2y+1→
y+3-y-1=2y+1-y-1→
2=y→y=2
2) CB must be congruent with ED→CB=ED→5x+7=6x+2y→
5x+7-5x=6x+2y-5x→7=x+2y→x+2y=7
Replacing y=2 in the equation above:
x+2y=7→x+2(2)=7→x+4=7→x+4-4=7-4→x=3
Then the lenght of each hypotenuse is:
CB=5x+7=5(3)+7=15+7→CB=22
or
ED=6x+2y=6(3)+2(2)=18+4→ED=22
The length of each hypotenuse is 22
You do cross multiplication so multiply 29 by 38 and then divide it by 78 which gives you answer of 14.128 cm