If you have multiple equations with multiple variables, you can either do clever substitutions, or turn it into a matrix on which you can perform linear combinations or multiplications (Gauss elimination)
1 1 1 1
2 1 -1 8
1 -1 1 -5
(note how the above 3 rows represent the 3 equations, just got rid of the variables, plus sign and equals sign)
subtract row1 from row3, that eliminates x and z from row 3.
1 1 1 1
2 1 -1 8
0 -2 0 -6
divide row3 by -2, that will give y a factor of 1
1 1 1 1
2 1 -1 8
0 1 0 3
The last row now says y=3
58% is about equal to 60%, 10% of 121 is 12.1.
12.1 * 6 = 72.6
To take this further, 58% is 2% less than 60%, or 2 times 1%. 1% of 121 is 1.21.
72.6 - (1.21 * 2) = 72.6 - 2.42 = 70.18
Select both the 2nd and 4th options!
59
47 - 11 = 36
23 + 36 = 59
I hope this helps. Brainliest appreciated.
Hi there!
I'm just gonna answer this and explain as I'm doing it.
So we have (3x10)x8= __x(10x8)
Well, first we look at what they did. They couldn't have changed the equation, but just moved things around.
Now, assuming you know your properties, I'm gonna go ahead and answer it.
(3x10)x8=3x(10x8)
^^
I used the Associative property, which basically says that when 3 or more #s are multiplied, the answer doesn't change no matter how you group the numbers. See how they just moved the numbers around, and only swapped the 3 for the 8?
Hope this helped!
