Answer:
Option 4th or the marked option is correct.
Step-by-step explanation:
The expressions are:
1. [tex]3a^{2} +5a-1-5a^{2}-3a+8[/tex]
Simplifying this by grouping same coefficients we get,
[tex](3a^{2} -5a^{2})+(5a-3a)+(8-1)[/tex]
= [tex]-2a^{2} +2a+7[/tex]
2. [tex]3a^{2} +4a+6- a^{2}-7a+1[/tex]
[tex](3a^{2} -a^{2})+(4a-7a)+(6+1)[/tex]
= [tex]2a^{2} -3a+7[/tex]
3. [tex]-7a^{2}-9a+4+5a^{2}+5a+3[/tex]
[tex](-7a^{2} +5a^{2})+(5a-9a)+(4+3)[/tex]
= [tex]-2a^{2} -4a+7[/tex]
4. [tex]a^{2}-6a+2+a^{2}-2a+5[/tex]
[tex](a^{2}+a^{2})+(-6a-2a)+(5+2)[/tex]
= [tex]2a^{2} -8a+7[/tex]
So, comparing all the answers, we can see that option 4th or the marked one is the correct matching.
