Answer:
63
Step-by-step explanation:
This is because 25% of 84 is 21. He knows how to play 21 songs. 84-21=63.
63 is how many songs he does NOT know how to play.
Answer:
1. Area of rectangular rug is 
2. Area of triangular room is 
Step-by-step explanation:
This problem bothers on the mensuration of flat shapes, rectangle and triangle.
step one
let us start by solving for the area of the rectangular rug
given data
Area A = ?
Length l = 11 ft
Width w= 10 ft
we know that the area of a rectangle is expressed as

substituting our given data we have

step two
let us solve for the area of the triangular room
given data
Area A = ?
base b = 30 ft
height h= 22 ft
we know that the area of a triangle is expressed as

substituting our given data we have

The area of the garden needs to be greater than 400 square feet but less than 600 square feet
2nd one, x^2 + 8x + 4
add 2x^2-x^2, 6x+2x, -3+7
Answer:
7.1 x 10³
Step-by-step explanation:
Move your decimal so that it follows your first whole number greater than zero. The number of places you moved the decimal is the same as the exponent. Since the number 7.1 needs to INCREASE to be 7,100, then the exponent is positive.