The algebraic expression is:
E = t + 10
Math uses numbers and equations, and science requires the scientific method and experimentation
An obtuse triangle has one obtuse angle, or an angle that measures more than 90° but less than 180°. Options 1 and 2 are not correct, because these are acute angles.
So, one of the angles must be 40°, and the other may be 100° or 120°.
The measures of the angles in a triangle add up to 180°.

The other two angles are 40° and 100°.
Answer:
a=223.57
c=181.43
Step-by-step explanation:
a=405-c
substitute for a in the equation :
12a+5c=3590
12(405-c)+5c=3590
4860-12c+5c=3590
-7c=3590-4860
-7c=-1270
c=1270/7=181.43
a=405-1270/7
a=1565/7=223.57