The answer is <span>He subtracted 10 from the right side instead of adding 10 to the right side
Let's solve it:
</span><span>2x + y = 5
x − 2y = 10
________
Rearrange first equation to get y:
y = 5 - 2x
________
Substitute y into the second equation:
x - 2(5 - 2x) = 10
________
Multiply the terms:
x - 10 + 4x = 10
________
Combine the terms:
5x - 10 = 10
________
Add 10 on the both sides of the equation:
5x = 10 + 10
5x = 20
x = 4</span>
Answer:
80.027
Step-by-step explanation:
139.65-59.623 = 80.027
1.) 1.67×10 to the power of 9
2.) 1.133×10 to the power of -3
3.) 1.75×10 to the power of 9
4.) 2.64×10 to the power of 4
5.) 2.947×10 to the power of -6
6.) 4.24×10 to the power of 5
7.) 1.0207×10 to the power of 6
8.) 1.027×10 to the power of 5