Answer:
x = 24.48, y = -15.52, z = 3.95 to the nearest hundredth.
Step-by-step explanation:
x+y-z=5 (a)
-x-4y-8z=6 (b)
3x+5y-4z=-20 (c)
Adding equations a and b:
-3y - 9z = 11 (d)
Now multiply equation b by 3:
-3x - 12y - 24z = 18 (e)
Adding c and e:
-7y - 28z = -2 (f) Multiply by 3 to give (g)
-3y - 9z = 11 (b) Multiply by -7 to give (h)
-21y - 84z = -6 (g)
21y + 63z = -77 (h) Adding g and h:
-21z = - 83
z = 3.952
and y is found bt substituting in equation d:
-3y - 9(3.952) = 11
y = ( 11 + 9(3.952) / -3
= -15.52.
Now find x by substituting for y an z in equation a:
x - 15.52 - 3.952 = 5
x = 5 + 15.52 + 3.952
= 24.476.
Answer:
Step-by-step explanation:
840
This is a proportion, she is walking 3.3 every hour. She walked for 5.4 hours. And we don't know how far she walked so its x/.54. Then you cross multiply which gives you 3.9×.54=x. We multiply those decimals and we get 1.782.
Answer:
a. x = 2 , x = -5
b. no real roots
Step-by-step explanation:
<u>a. x² + 3x – 10</u>
= x² - 2x + 5x - 10
= x (x²/x - 2x/x) + 5 (5x/5 - 2*5/5)
= (x - 2) (x + 5)
x - 2 = 0 x + 5 = 0
+ 2 +2 -5 -5
-------------- ---------------
x = 2 x = -5
x = 2 , x = -5
<u>b. 2x² - 4x + 3 </u>
This can't be solved because the equation has no real roots, and also the discriminant is negative.
I believe the answer is D. 1.121, 1.21, 1.432, 1.53
