Answer:
(x + 7)^2 = 64
Step-by-step explanation:
x^2 + 23x – 19 = 9x - 4
x^2 + 23x - 9x = -4 + 19
x^2 + 14x = 15 = 0
Completing the square:
(x + 14/2)^2 - (14/2)^2 = 15
(x + 7)^2 - 49 = 15
(x + 7)^2 = 64
I don't quite understand the ten strategy, or what EXACTLY you're asking. But, what you can do is when you add a one digit number plus a nine, just change the nine to a ten and subtract one. It is very easy. So, 7+10 equals 17, subtract one and you get 16 which is 7+9. It is always one less than anything plus 10.
Answer:
37 and 27
Step-by-step explanation:
Lets say that the two numbers are x and y. We get the equations x + y = 64 and x - y = 10. We can then add these two equations together to get, 2x = 74. Then we divide by two on both sides and get x = 37. We then plug this value back into the second equation and get that 37 - y = 10. We can simplify this and we get that y = 27. So our two numbers are 37 and 27.
Seven hundred and and eighty thousand