Factorise the following (a+b)⁴-(a-b)⁴​

Liz had 140 pens and inna had 100 pens. after inna gave liz some pens, liz had 3 times as many pens as inna. how many pens did inna give liz?

The graph and table shows the relationship between y, the number of words jean has typed for her essay and x, the number of minutes she has been typing on the computer. according to the line of best fit, about how many words will jean have typed when she completes 60 minutes of typing? 2,500 2,750 3,000 3,250

Out of 50 students surveyed, 16 have a dog. based on these results, predict how many of the 280 students in the school have a dog.