Why is this true 7a+4-2a=7a+ -2a+4​

Step-by-step explanation:

Notice that both sides involve 7a - 2a, and both involve 4.  By the associative property the order in which the addends appear is immaterial; the left side therefore equals the right side.

7a + 4 - 2a = 7a - 2a + 4

5a + 4 = 5a + 4

Step-by-step explanation:

7a + 4 - 2a = 7a - 2a + 4

​7a + 4 - 2a

Rearrange the terms.

7a - 2a + 4

Combine like terms.

5a + 4

The left side simplifies to 5a + 4.

7a - 2a + 4

5a + 4

The right side also simplifies to 5a + 4.

step-by-step explanation:

there is a formula i can give you:

it is r^2*n*sin(360/n) divided by 2 where r represents the "radius" and n is the number of sides.

plug them in:

(10sqrt(3))^2*6*sin(360/6) divided by 2

100*3*6*sin(60) divided by 2

900*sin(60)

900*sqrt(3)/2

450*sqrt(3)

approx is 779.4 cm^2