2 years ago

Twice a number (z) added to 21 is equal to 9 times the number added to 7. What is the number?

Mathematics

1 answer:

pickupchik [31]2 years ago

5 0

Answer:

The number is 2

Step-by-step explanation:

Twice a number (z) = 2*z = 2z

Twice a number (z) added to 21 = 2z + 21

9 times the number added to 7 = 9z + 7

9z + 7 = 2z + 21

Subtract 2z form both sides

9z - 2z + 7 = 21

7z + 7 = 21

Subtract 7 from both sides

7z = 21 - 7

7z = 14

Divide both sides by 7

z = 14/7

z = 2

You might be interested in

Plwees help:)

drek231 [11]

Dan takes about 8 minutes to run a mile

Yoko payed around $1.75

8 0

2 years ago

Are the ratios 2.5:3.5 and 5:7 proportional? explain

yuradex [85]

$\frac{2.5}{3.5}=\frac{2.5 \times 2}{3.5 \times 2}=\frac{5}{7}$

They are the same fraction, so they are proportional.

3 0

2 years ago

Y varies directly as x if x=15 when y=20, find x when y=30

mixas84 [53]

Answer:

X=22.5

Step-by-step explanation:

Y=kX

20=15k

k=4/3

For X when Y=30

30=4/3×X

Cross multiply

4X=90

X=22.5

6 0

2 years ago

You are walking away from home at a constant velocity of 5 km per hour. The first landmark you see is your favorite fountain whi

Reptile [31]

R=5km
D=2km

T=D/R

T=2km/5km

4 0

3 years ago

HELP DONT TRY ME I WILL REPORT IF WRONG ANSWER FAST I WILL +BRAINLIEST

Neporo4naja [7]

Answer:

I think its 2/3 x 4

7 0

2 years ago