Question

Can someone help me PLEASE

Answer 1

Let's solve this problem step-by-step:

`7 * 9 = (7*10)-(7*x)`

• x: it is the delta in the equation given in your picture

We know (7*10) - (7*x) is equivalent to the 7*(10-x)

⇒ based on the Distributive Properties

`a*(b+c) = ab + ac`

`7*(10+(-x))=(7*10)+(7*(-x)=(7*10)-(7*x)`

So:

`7*9=7(10-x)\\9=10-x\\x=10-9\\x= 1`

Thus delta (the little triangle in this problem) in this case is 1

Answer: 1

Hope that helps!