X + 5y = 1 . . . . (1)
8x - 2y = 3 . . . .(2)
Solution 1.
From (1), x = 1 - 5y
substituting for x in (2), we have:
8(1 - 5y) - 2y = 3
8 - 40y - 2y = 3
8 - 42y = 3
42y = 5
y = 5/42
x = 1 - 5(5/42) = 1 - 25/42 = 17/42.
Solution 2.
Multiply (1) by 8, to get:
8x + 40y = 8 . . . . . (3)
(3) - (2) = 40y - (-2y) = 8 - 3
42y = 5
y = 5/42
substitute for y into (3), to get:
8x + 40(5/42) = 8
8x + 100/21 = 8
8x = 8 - 100/21 = 68/21
x = (68/21)/8 = 17/42
Step-by-step explanation:
The answer is mentioned above.
13. 1,6
18. -15,12
19. -7, 1/2
Answer: y=kx/w^2
Step-by-step explanation:
y is directly proportional to x
y∝x
y=kx
y inversely proportional to the square of w.
y ∝ (1/(w)^2)
y=k/w^2
y=kx/w^2
Answer:
13.18651685
13.9
Explain:
890-238=652
652/890=0.7325842697 (Find out the percentage)
We know that 1 gram of Element X will be fully decayed in 18 minutes and half of it in 9 minutes.
0.7325842697x18=13.18651685
As you see 18/13.18651685 will equal to 18 (not exactly since it is rounded)
And of course we need to round it to nearest tenth. So the answer would be 13.9!
