Answer:
Step-by-step explanation:
3+4=8-x
x=8-7
x=1
Suppose the number of 2 hours lessons are x and 1 hour lessons are y; thus,
2x+y=25
50x+30y=690
to get the values of x and y we solve the quadratic equation given;
from the top equation:
y=25-2x.......i
substituting i in our second equation we get:
50x+30(25-2x)=690
50x+750-60x=690
-10x=-60
thus;
x=6
hence we conclude that the number of 2 hours classes are 6 hours
Answer:
percent decrease
26%
Step-by-step explanation:
Yesterday you ran 5 miles
Today you ran 3.7 miles
The amount went down, so the percent decreased
The percent decrease = (original - new)/original * 100 %
= (5-3.7)/5 * 100%
= 1.3/5 * 100 %
=.26 *100%
= 26%
If you would like to know what was the percent decrease in price, you can calculate this using the following steps:
x% of $299.99 is $180.55
x% * 299.99 = 180.55
x/100 * 299.99 = 180.55
x = 180.55 * 100 / 299.99
x = 60.19%
100% - 60.19% = 39.81%
The correct result would be 39.81%.
This is the concept of algebra, for us to calculate the area of the triangle we need the value of x. Therefore, we shall obtain this from the perimeter.
P=6x+4x+3x=18
13x=18
x=18/13
x=1.385
The length of the altitudes will be:
6x=6×1.385=8.31
4x=4×1.385=5.54
3x=3×1.385=4.155
the area will be given by Heron's formual:
Area=√[p(p-a)(p-b)(p-c)]
p=(a+b+2)/2
=(8.31+5.54+4.155)/2
=9.0025
therefore:
A=√[9.00(9-8.31)(9-5.54)(9-4.155)
A=104.64 sq. units