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
how come you need help? It is super easy. Just combine Like Terms.
https://www.khanacademy.org/math/cc-sixth-grade-math/cc-6th-expressions-and-variables/cc-6th-combining-like-terms/v/combining-like-terms-1
That is a website for help!
Answer:
The given triangle ABC is a SCALENE RIGHT - ANGLED TRIANGLE
Step-by-step explanation:
Here, in the triangle ABC
∠A = 90° , ∠B = y+ 40° and ∠C = 3y - 10°
Now, by ANGLE SUM PROPERTY of a triangle:
∠A + ∠B+ ∠C = 180°
or, 90° + ( y+ 40°) +( 3y - 10°) = 180°
or, 4y + 120° = 180°
⇒ 4y = 180° - 120° = 60°
or, y = 60° / 4 = 15 ⇒ y = 15
⇒ ∠B = y+ 40° = 55°
and ∠C = 3y - 10° = 3(15) -10 = 35°
Now, here ∠A = 90° , ∠B = 55° and ∠C = 35°
Since here ∠B ≠ ∠C ≠ 45°
Hence, the given triangle ABC is a SCALENE RIGHT ANGLED TRIANGLE
