Simplify: -2(a-3b)-4a+7b expand and simplify: 3(7x-2y)-5(2x+y), 4h(k-3h)-6k(h-9k), (5b-7)(3+6b), (7b+3)(5-2p)-(4-3p)(p-1)
factorise: a²+5a-6, 12a²-19d+5
factorise using identities of algebra:4k ²+12k+9,81a ²-49b ²

(a) calculate the molarity of a solution that contains 0.0345 mol nh4cl in 400 ml of solution. (b) how many moles of hno3 are present in 35.0 ml of a 2.20 m solution of nitric acid? (c) how many milliliters of 1.50 m koh solution are needed to supply 0.125 mil of koh ?

If 3x+8=3x+8 is it one solution or no solution

The table below shows the approximate height of an object x seconds after the object was dropped. the function h(x)= -16x^2 +100 models the data in the table. for which value of x would this model make it the least sense to use? a. -2.75 b. 0.25 c. 1.75 d. 2.25