Answer:
(4, 3)
Step-by-step explanation:
#1. Isolate x:
3x + y = 15
y = 15 - 3x
Substitute and solve for x:
5x - 3y = 11
5x - 3(15 - 3x) = 11
5x - 45 + 9x = 11
5x + 9x = 11 + 45
14x = 56
x = 4
Substitute and solve for y:
y = 15 - 3x
y = 15 - 3(4)
y = 15 - 12
y = 3
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:
the square root is probably 2
Step-by-step explanation:
Answer:
Step-by-step explanation:
take 60 degree as reference angle
using cos rule
cos 60=adjacent/hypotenuse
1/2=80/x(do cross multiplication)
80*2=x
160=x