3 years ago

What number completes this sentence12/18=x/30

Mathematics

1 answer:

BartSMP [9]3 years ago

5 0

Cross multiplying:-
18*x = 12*30
x = 360 / 18

x = 20 answer

You might be interested in

What is the ratio for each one?

blagie [28]

This is complicated because I’m typing on a phone, but
24:30 simplified is 4:5
30:54 simplified is 5:9

10:5 simplified is 2:1
5:15 simplified is 1:3

32:72 simplified is 4:9
72:104 simplified is 9:13

56:7 simplified is 8:1
7:63 simplified is 1:9

8 0

3 years ago

1/4(1/3k+9)=6 step 1- 1/3k=15 step 2- 1/3k=15 step 3- k=5 find Olgas mistake step 1 step 2 steps 3 Olga did not make a mistake

shtirl [24]

Answer:

Step 3 contains error.

Step-by-step explanation:

The given equation is :

$\dfrac{1}{4}(\dfrac{1}{3}k+9)=6$

Step 1.

Cross multiplying,

$(\dfrac{1}{3}k+9)=24$

Step 2.

Subtract 9 from both sides

$\dfrac{1}{3}k+9-9=24-9\\\\\dfrac{1}{3}k=15$

Step 3.

Cross multiplying

$k=15\times 3\\\\k=45$

So, there is an error in step 3. The correct answer should be 45.

3 0

2 years ago

The line with equation x-3y-27=0 meets the parabola y²=4x at two points. Find their coordinates

lesantik [10]

$x-3y-27=0\\
y^2=4x\\\\
x-3y-27=0\\
x=\frac{y^2}{4}\\\\
\frac{y^2}{4}-3y-27=0\\
y^2-12y-108=0\\
y^2-12y+36-144=0\\
(y-6)^2=144\\
y-6=-12 \vee y-6=12\\
y=-6 \vee y=18\\\\
x=\frac{(-6)^2}{4} \vee x=\frac{18^2}{4}\\
x=\frac{36}{4} \vee x=\frac{324}{4}\\
x=9 \vee x=81\\\\
\boxed{(9,-6),(81,18)}
$