25. The product of 8 and the difference between a number and 9 is 96. What is the number? The answer is 13. So, 8*(x-9)=96 8*12=96 So, what number minus 9=12? 13.
26. When 12 is added to half the sum of a number and 8, the result is 40. What is the number? The answer is 40. 12+ (x+8)=40 12 +28=40, so what plus 8 =28? 20. 20 times 2 is 40.
27. The difference between a number and 5, when multiplied by 3, is 36. What is the number? The answer <em />is 17. (x-5)*3=36 12*3=36, so what minus 5=12? 17.
SinB = cosC = AC / BC = 8/10 = 4/5; tgB = ctg C = AC/AB = 8/6 = 4/3, because we use T. Pitagora for calculating AB; sinC = cosB = AB/ BC = 6/10 = 3/5; tgC = ctgB = AB/ AC = 6/8 = 3/4.
