Answer:
C = 72
Step-by-step explanation:
It's [0, 68]. To find the product of these, perform the following: [(3*4)+(-1*2)+(-2*5)]=0 and [(5*4)+(4*2)+(8*5)]=68
So you've got:
6.4x + 2.8y = 44.4
You want to know the value of (y) when x=3:
6.4 * 3 + 2.8y = 44.4
(6+0.4) * 3 + 2.8y = 44.4
18 + 1.2 + 2.8y = 44.4
19.2 + 2.8y = 44.4
2.8y= 44.4 - 19.2
2.8y = 25.2
y=(25.2)/(2.8)
y=9
(2,5 x 10^-10)(7 x 10^-6) = (2.5 x 7) x 10^(-10 - 6) = 17.5 x 10^-16 = 1.75 x 10^-15