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:5a-30=45
Step-by-step explanation:
So something times 5 minus 30 will give you 45
Multiply all the numbers by 2 first, so 12 yards 18 ft 8 in. After that, you simplify. There are three feet in a yard, so in eighteen feet there are 6 yards. That makes 18 yards and 8 in
Answer:
A
Step-by-step explanation:
The student must have thought that every single arrowhead is a line of symmetry, so since there are 10 arrowheads, there must be 10 lines of symmetry. This is incorrect because if you look closely at the diagram, each line has 2 arrowheads, so the student is overcounting by a factor of 2. They should have just counted the number of lines, not arrowheads. Therefore, there must be 10/2 = 5 lines of symmetry, not 10. Hope this helps!
The red area is the one which solves the system. In fact, we want the area which below both the parabola and the line (since the inequality features a 
sign.
So, the point 
is below the line but above the parabola (blue area), so it is not a solution.
The point 
is above both the line and the parabola (white area), so it is not a solution.
The point 
is below both the line and the parabola (red area), so it is a solution.
So, the point 
is below the parabola but above the line (green area), so it is not a solution.
