XERCISE 8 (3) Factorise the following quadratic trinomials fully: (1) (2) (4) (5) a’ -9a+20 (7) a² - 12a+35 (8) (10) m² - 5m - 6 m (11) m² + 5m-6 (13) x2 + 7x+12 + (14) r? – 7x+12 Factorise fully (1) 2r2-21-12 (2) 3x? - 21x-54 (4) 6a2 +24a - 30 (5) x² + 2x² – 8x Explain why the trinomial x?+ 4x + 5 cannot factorise (6) (9) (12) (15) a? -11a-12 m² + 5m + 6 m2 - 5m + 6 + - - (3) (6) 4a? +12a-40 90 – 45x + 5x2 -

Matt and brian were solving a system of equations. they both noticed that the two lines had the same slope. brian said that because each line in the system had the same slope, the two lines had to be parallel, which meant the solution to the system was "no solution" matt disagreed, and said they should also look at the y-intercepts before determining how many solutions there were. who is correct?

The brain volumes (cm cubed) of 50 brains vary from a low of 904 cm cubed to a high of 1488 cm cubed. use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 175.5 cm cubed, assuming the estimate is accurate if it is within 15 cm cubed

Paula makes stained-glass windows and sells them to boutique stores. if her costs total $12,000 per year plus $4 per window for the frame. how many windows must she produce to earn a profit of at least $48,000 in one year if she sells the windows for $28 each? 1. define a variable for the situation. 2. write an inequality that represents her profit. note: revenue is money coming in. cost is money going out. profit is the difference between the revenue and the cost. in other words: revenue - costs profit 3.using words, describe how many windows she must sell to have a profit of at least $48,000.