Solve using substitution.
-7x + 9y = 20
y = 10

x=10

Step-by-step explanation:

1. substitute y for 10 getting -7x +9(10)=20

2. 9(10)= 90

3. with -7x+90=20 subtract 90 on both sides getting -7x= -70

4. then divide by -7 on both sides getting x=10

5. to check u substitute x with 10 and y with 10 getting -7(10)+9(10)=20. then multiply and add/subtract to get 20=20

(f - g)(x) = 5x^3 - 3

step-by-step explanation:

rearrange these functions vertically, with like terms in separate columns:

f(x) = 5x^3 - 2

g(x) =         +1

now subtract, column by column:

(f - g)(x) = 5x^3 - 3

0.02

step-by-step explanation:

time of 9 192 631 770 periods of the radiation corresponding to the transition between the 2 hyperfine levels of the ground state of the caesium 133 atom at 0 k (but other seconds are sometimes used in astronomy)