Hello, To find common multiples we can look at the 4 and 6 table or (4*1,4*2,4*3 written as a chart) 4:4,8, 12, 16, 20, 24, 28, 32, 36, 40 6:6, 12 ,18, 24, 30, 36, 42, 48, 54, 60 As you can see both charts have 24 so a common multiple of 4 and 6 is 24.
X=the number we have to find. This expression "2(x+9)" is when the sum of a number and nine is doubled. If the result is seven less than the number, we will have: x-7
We can suggest the following equation: 2(x+9)=(x-7) 2x+18=x-7 2x-x=-7-18 x=-25