Answer:
The specific gravity of kerosene is 0.82
Step-by-step explanation:
Let
x -----> the weight in grams of a cubic centimeter of Kerosene
y ----> the weight in grams of a cubic centimeter of water
z ---> the specific gravity of a substance
so

we have

substitute the values

<span> x - 4y = -5
-x + 6y = 7
---------------add
2y = 2
y = 1
</span> x - 4y = -5
x - 4(1) = -5
x - 4 = -5
x = -1
answer
x = -1 and y = 1
Answer:
hope it's helpful.........
From the amounts that are given, the ratio of the earnings will be 3:2:1.
<h3>How to calculate ratio</h3>
From the information, the eldest earns R270, the middle child earns R180 and the youngest earns R90.
Therefore, the common factor to the numbers will be 90. Therefore, the ratio will be:
270/90 = 3
180/90 = 2
90/90 = 1
The ratio is 3:2:1.
Learn more about ratio on:
brainly.com/question/2328454