<span>−8x+7y=25 is already in standard form, altho some people would prefer to re-write it as
</span><span>−8x+7y-25 = 0.
You have shared 4 equations here. Next time, please separate them with commas or semi colons, or type just 1 equation per line, for increased clarity. Thanks.</span>
The second condition tells you that

is half the size of

, so

, which could be rewritten in several ways. In standard form, that would be

.
Answer:
B
Step-by-step explanation:
2a+45=180
subtract 45 from both sides which equals 2a=135
divide both sides by 2 which would solve for a.