If set a = {3, 4, 7, 9}, set b = {8, 9, 10, 11}, and set c = {4, 9, 11, 13, 15}, then a∩(b∪c) =

{}
{4, 9}
{3, 4, 7, 9, 11}

A = {3, 4, 7, 9}

B = {8, 9, 10, 11}

C = {4, 9, 11, 13, 15}

A∩(B∪C)

First let's solve parentheses, we want the union between B and C.

B∪C = {4, 8, 9, 10, 11, 13, 15}

Now we want the interception between A and this, which means we want just the value which appears in both.

A∩{4, 8, 9, 10, 11, 13, 15} = {4, 9}

answer: bearing in mind that a rectangle has a perimeter of length + length + width + width.

step-by-step explanation:

p = perimeter

l = length

x=width

p = 2l + 2x

p = 2(l+x)     < ==== perimeter of the base of the box.