14(b) B1 5( y 2) – 12w + 3 15w + 10 – M1 Allow one sign or arithmetic error for M1 (12w + 3) (15w 10) – – 12w + 3 15w + 10 A1 A1 if all correct – ft their expansion if M awarded 14(c) 3w + 13 A1ft Ignore any non-contradictory further work, – such as solving an equation, but do not award A1 if contradictory further work, such as = 10w B1 if 4 or 5 plotted correctly 15(a) Points plotted correctly B2 ± small square Mark or LOBF on graph within range M1 (25, 40) to (25, 44) 15(b) ft their line or their mark SC1 if no marks or no LOBF shown and 40 44 A1ft – answer in range [40, 44] Shows sales and temperature for two points either side of 25, eg one of (20, 36) or (21, Any attempt at interpolation or ‘build 37) or (22, 39) and (29, 47) M1 up’ or a calculation such as 39 15(b) + 3 (47 39) ÷ 7 Alt –  SC1 if the is not convincing ‘interpolation’ 40 44 A1ft – but answer in range [40, 44] No as the sales at low temperatures are constant 15(c) B1 At low temperatures sales do not increase No as at 9° sales are (about) same 16(a) Pearl or 1.7 B1 3 16(b) B1 oe 5 5 58 (= 290) + 64 (= 354) M1 (64 58) ÷ 6 (= 1) –  16(c)
14(b) 5( y – 2) B1 14(c) 12w + 3 – 15w + 10 (12w + 3) – (15w – 10) M1 Allow one sign or arithmetic error for M1 12w + 3 – 15w + 10 A1 A1 if all correct ft their expansion if M awarded – 3w + 13 A1ft Ignore any non-contradictory further work, such as solving an equation, but do not award A1 if contradictory further work, such as = 10w 15(a) Points plotted correctly B2 B1 if 4 or 5 plotted correctly ± small square 15(b) Mark or LOBF on graph within range (25, 40) to (25, 44) M1 40 – 44 A1ft ft their line or their mark SC1 if no marks or no LOBF shown and answer in range [40, 44] 15(b) Alt Any attempt at interpolation or ‘build up’ M1 Shows sales and temperature for two points either side of 25, eg one of (20, 36) or (21, 37) or (22, 39) and (29, 47) or a calculation such as 39 + 3  (47 – 39) ÷ 7 40 – 44 A1ft SC1 if the ‘interpolation’ is not convincing but answer in range [40, 44] 15(c) No as the sales at low temperatures are constant No as at 9° sales are (about) same B1 At low temperatures sales do not increase 16(a) Pearl or 1.7 B1 16(b) 3 5 B1 oe 16(c) 5  58 (= 290) + 64 (= 354) M1 (64 – 58) ÷ 6 (= 1)