Algebra problems helppppp

(1)19/7(2) 19/3(3) 3(4) 74) the expression (√5-2) (√5+2) is equivalent to (1) 1 (2) √5-4(3) 3(4) 4-√5-1) solve for x: 5x-7=28 (1) 7 (2) -7 (3) 5 (4) -55x-7=28add 7 to both sides5x=35x=7(1) 2) which property is illustrated by the equation 5+(2+3)=(5+2)+3? (1) distributive (2) commutative (3) associative (4) identity(4) [I think]:D 3) which value of p is the solution of 5p-1=2p+20? (1)19/7 (2) 19/3 (3) 3 (4) 75p-1=2p+20subtract 2p from both sides3p-1=20add 1 to both sides3p=21p=7(4) 4) the expression (√5-2) (√5+2) is equivalent to (1) 1 (2) √5-4 (3) 3 (4) 4-√5this is a difference of squaresyou need to get use to spotting themthey pop up EVERYWHEREdifference of squaresx^2-y^2=(x+y)(x-y)so, (√5-2) (√5+2)is derived from (√5^2-2^2) √5^2=52^2=45-4=1(1)-5x - 7 = 28 first add 7 to both side5x = 28 + 7 this give5x = 35 then divide across by 5x = 7 which give (1) for the answerPROOF: Substitute 7 back into the original equation.5 x 7 - 7 = 2835 - 7 = 2828 = 28correct!Distribution (1)5p - 1 = 2p + 20 first add 1 to each side of the equation5p = 2p + 20 + 1 which is equal to 5p = 2p + 21Now take 2p from each side of the equation5p - 2p = 21 which gives us3p = 21 then divide each side of the equation by 3p = 7PROOF: Substitute result back into the equation5 x 7 - 1 = 2 x 7 + 2035 - 1 = 14 + 2034 = 34 correct!......