SOLUTION: please help me, Area of a triangle is 30 square meter. Find the base and altitude, if the altitude exceeds the base by 7 meters. please....

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Question 662611: please help me,
Area of a triangle is 30 square meter. Find the base and altitude, if the altitude exceeds the base by 7 meters. please....
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

given:
A=30m%5E2

let the base be b and altitude h,
if the altitude exceeds the base by 7m, we have h=b%2B7m

A=%281%2F2%29b%2Ah
30m%5E2=%281%2F2%29b%2A%28b%2B7m%29
30m%5E2%2A2=b%2A%28b%2B7m%29
60m%5E2=b%5E2%2B7bm
b%5E2%2B7bm-60m%5E2=0 ...use quadratic formula to solve for b

b+=+%28-7m+%2B-+sqrt%287%5E2-4%2A1%2A%28-60m%5E2%29+%29%29%2F%282%2A1%29+

b+=+%28-7m+%2B-+sqrt%2849%2B240m%5E2%29+%29%29%2F2+

b+=+%28-7m+%2B-+sqrt%28289m%5E2%29+%29%29%2F2+
b+=+%28-7m+%2B-+17m+%29%2F2+...we need only positive root
b+=+%28-7m+%2B+17m+%29%2F2+
b+=+10m%2F2+
highlight%28b+=+5m%29+

now find h=b%2B7m
h=5m%2B7m
highlight%28h=12m%29