Answer:

Step-by-step explanation:
Let x be cost of 1 eraser.



Answer:
so just successive powers of 2
Step-by-step explanation:
1, 3, 7, 15, 31, 63, _? Add successive powers of 2 to the number: 1+2=3; 3+4=7; 7+8=15; 15+16=31; 31+32=63; 63+64=127.
The range is 47 hope it helps <3
We first simplify the equation: 0.1x = 0.2x + 0.2 * 2, then we move the left side 0.1x to the right side, the 0.2 * 2 to the right side and we have -0.4 = 0.2x - 0.1x, then we have -0.4 = 0.1x, so we have x = -4